"How does one address a duke?" Rose asked, looking up from the depth of her easy-chair.

"No idea," I replied. "I don't suppose we shall see anything of him."

"I only knew one," Leonard murmured reminiscently. "He was at Harrow and we used to call him Tubby."

"I don't see that that's going to help us," Rose remarked. "However——"

Then the door of our sitting room opened and to our surprise our host entered. He bowed to Rose and nodded to us in friendly fashion.

"Very good of you to come down here and help us along," he said, pleasantly ignoring the fact that we were being paid fifty pounds a week and our expenses to help provide his guests with entertainment. "I hope you're quite comfortable?"

We all three murmured an unqualified affirmative. The arrangements made for our comfort were indeed beyond criticism.

"You're not any relation to the Cotton who started bowling googlies for Harrow in his last term, I suppose?" the Duke queried, addressing Leonard.

Leonard modestly pleaded guilty, and our host showed his first signs of real interest.

"You'll play for the Castle this afternoon?" he begged. "We're playing the rest of the County, and they're bringing a pretty hot side. Our batting's all right but our bowling's rotten."

"I haven't played for two years," Leonard said, a little doubtfully.

"At three o'clock," the Duke announced, ignoring Leonard's hesitation. "You'll find a couple of pros down at the nets if you want a knock first. Don't give your bowling away too much, as some of the enemy are prowling around."Our host took gracious leave of us. Rose watched him curiously.

"Maurice," she observed, as the door closed, "there's something queer about this place."

"I suppose there must be," I admitted, "or we shouldn't be here."

"Exactly what are our instructions?" Leonard enquired.

"Vague," I replied. "The only letter I received from our chief told me to accept the offer through Keith Prowse, to come here, to sit tight and study conditions."

"What did he mean by 'conditions'?" Rose asked.

"Just get in touch with our environment, I suppose. For instance, here we are with half a dozen others, brought up to Westmoreland to amuse the Duke's house party. We are being treated royally, the house party seems to comprise some of the best-known names in England, and the whole thing seems to be marvellously done."

"But so far no glimmering as to how or where we may come in?" Leonard persisted.

"Not the slightest," I admitted. "Of course, this place is a perfect treasure house. They say that the jewels alone are insured for more than two millions. There may be some robbery scheme on."

"Perhaps," Rose suggested, "we are to be the thieves. In that case, I'll keep one of the famous pink pearls if I have to swallow it."

I looked out across the park and a certain feeling of depression stole over me. We were alone in a little sitting room which had been made over to our exclusive use.

"I can't help wishing," I confessed, "that we knew a little more where we stood. We've been working for Mr. Thomson now for the best part of a year, and there isn't one of us three can tell whether we've been helping the greatest crook the world has ever known, or a master detective."

"I'm not sure that I care," Rose said sweetly.

Leonard helped himself to a cigarette.

"When I think of that night at Cromer," he reflected—"you remember how wet it was, how the wind howled, and we hadn't enough fire in our lodgings, or enough money to buy food?—when I think of those days and realise how life has changed since our mysterious god came out of the machine, I feel very much like Rose. I feel like a pagan, Maurice. We're back again in our old lives, wearing the right sort of clothes, eating and drinking like civilised beings, travelling in comfort, and with a bank account growing all the time. It's good enough for me."

"And for me," Rose echoed.

I fell in with their mood. After all, the sun was shining and a long summer's day lay before us.

"Begone, dull care," I invoked, "at any rate until our next letter of instructions arrives. Into flannels, Leonard, and then to the nets. I suppose they'll let me have a knock."

"I shall come and watch," Rose decided graciously.

Our entertainment at Lorringham Castle was in its way princely. We had a suite of rooms to ourselves, and a dining room which we shared with Charles Jacoty, the leader of the Duke's private orchestra, David Faraday, the famous illusionist, a Mrs. Middleham, widow of the Duke's private chaplain, who arranged the dance programmes and painted the menus, and a young man—Gerald Formby—the son of Sir James Formby, the agent to the estate, who presided at the dinner table and from whom we heard most of the gossip of the place. It was on the evening after the cricket match that we received from him the first inkling as to what the nature of our mission might be.

"Have you seen the Lorringham treasures yet?" he asked Rose.

She shook her head.

"I don't even know what they are."

The young man appeared incredulous.

"You mean to say that you haven't heard of the Lorringham pearls and the seven tiaras?"

"I've heard of them vaguely," she replied. "I didn't even know that they were on view."

Jacoty leaned a little forward in his chair. Faraday also appeared to be interested. The young man lowered his voice a little. There was inherited awe in its inflexion."The Lorringham pink pearls," he said, "are the most famous in history, although they are very seldom seen. They were last worn, in fact, by Eleanor, Duchess of Lorringham, at Queen Victoria's wedding. The seven tiaras are famous throughout the world. The earliest dates from the time of Charles the First."

"And they are really on view?" Rose asked.

"Not to the public. Whenever there is a house party here, they are generally shown to the guests."

"They are immensely valuable, these jewels?" Faraday enquired.

"They are insured for two millions," was the young man's portentous reply.

There was a little silence. I chanced to glance at Faraday, and I was almost startled by the gleam in his sunken eyes. He sat like a man in a brown study, tapping the tablecloth with his fingers.

"Has any attempt at robbery ever been made?" Leonard asked.

Gerald Formby shook his head.

"They are too well guarded," he said."It is interesting, this," Faraday remarked quietly. "Are the jewels kept in safes?"

The young man smiled.

"The room in which they are is in itself a safe. There are steel shutters to the windows, and steel safes let into the wall. There is a man on guard outside, day and night, and the only key in existence which could unlock the safes is in the possession of the Duke himself."

My eyes met Leonard's. For the first time I understood the only three words of admonition which we had received:

Watch the Duke.

Faraday spoke what was in my own mind.

"That fact may do away with some risk," he observed, "but isn't it rather a danger to his Grace? Fancy being in constant possession of a key which secures a treasure like that!"

"And you mean to say that no one has ever made any attempt to steal them?" Rose asked.

"Once only, twenty-two years ago, in the late Duke's time," Formby admitted. "A gang of burglars—they say that Charles Peace was one of them—broke into the Castle, but they never got anywhere near the room. Soon after that these shutters were built, and the safes let into the wall, and quite recently an American expert came over, who designed the lock. Robbery is now an impossibility."

We gave our first performance later on that evening. The Duke himself came up and congratulated us afterwards. He invited us to join the rest of the guests, a courteous offer of which, however, we did not avail ourselves.

"You will at least join my personally conducted party," he suggested, turning to Rose, "and have a look at the Lorringham treasures? I am taking a few of my guests there at eleven o'clock. I shall expect you three."

We accepted that invitation willingly enough, and the Duke returned to his guests. Afterwards, Faraday gave one of the most astonishing performances of sleight of hand I have ever seen. With scarcely any appliances, he succeeded in puzzling everybody. One of the guests, selected at random, was made to disappear in such a fashion that he himself, when questioned afterwards, was utterly confused about his experience. Later on he brought a locked-up mastiff from his kennel and a singing bird down from the top of the great hall. The Duke, with several of his companions, came up to congratulate the illusionist. Faraday received their compliments with the grave pleasure of one who recognises his supremacy. As the Duke was leaving, he addressed him.

"I heard your Grace inviting Miss Mindel and her companions to inspect the treasure chamber to-night," he said. "May I be permitted to accompany them?"

The Duke seemed on the point of giving a ready consent, then suddenly he hesitated. He looked at Faraday with a dubious smile.

"After that performance of yours, Mr. Faraday," he confessed, "I really don't know what to say. I seem to have a horrible vision of watching my tiaras come out through the steel doors, and my pink pearls drop out from the ceiling into your waistcoat pocket."Faraday did not smile. It seemed to me that he was very much in earnest.

"I will undertake to refrain from any extempore performance," he said. "As a matter of fact, your Grace, there are limitations to my magic."

The Duke turned away. He seemed rather to resent the other's persistence.

"Another time, perhaps," he promised, a little coldly. "My party to-night is made up."

Faraday was standing a little in the shadows and I watched him eagerly. From that moment our mission to Lorringham Castle seemed to become clearer to me.

An hour or so later, our host led a small company of us to the treasure chamber. We paused outside a green baize door leading into one of the galleries, which was guarded by a servant in the livery of the house. The Duke, with a word of apology, took off his coat and rolled up his shirt sleeves, disclosing a plain platinum band around his arm.

"This is an American idea," he explained.

He touched a spring in the band, one side opened and disclosed a key, attached to a thin chain of platinum wire. With this he unlocked the door of a small chamber, brilliantly lit. One side of the room seemed to be composed, up to the height of about six feet, of solid steel shutters. The Duke fitted the other end of the key into a concealed crevice. There was a little click, and the whole of the shutters rolled back. From behind windows of solid plate-glass, on a background of black velvet, were displayed the famous tiaras, rows of marvellous pearls, some of them as large as marbles and pink as sea coral, and a further collection of magnificent jewellery. There seemed to be an almost universal gasp of astonishment. The women of the party especially were speechless.

"We keep them like this instead of in coffers," the Duke explained, "so that they can be shown without being handled."

"Supposing you wanted to get at them?" some one asked.

"There is a secret spring," he replied, "which releases these windows. You should look at the diamonds in that Queen Anne tiara, Lady Mordaunt," he added, turning to one of his guests. "The greatest diamond expert in the world, who was here last year, declared that he had never seen stones to match those in his life."

We gazed, we admired, we marvelled. In a few minutes the show was over, the doors locked, the key back in its wonderful hiding place, and the Duke's coat once more hanging from his shapely shoulders.

"I don't wear this platinum affair except when I am down here," he told us. "The rest of the time I leave it at my banker's. Tell me what you are thinking about, Miss Mindel?" he asked, turning to her with a smile.

Rose answered him frankly.

"I was wondering why you wouldn't let Mr. Faraday come with us."

The Duke frowned slightly.

"Well," he admitted, "I suppose it was foolish of me. All the same, the man's performance took away my breath. Of course," he went on, "I know that it was all illusion, and yet it doesn't seem to me any more wonderful to think of his thrusting his hand through my plate-glass windows and helping himself to my pearls, than to perform some of the feats he achieved this evening. The guardianship of several million pounds' worth of family treasures," he concluded, with an apologetic smile, "sometimes tends to make one unreasonable."

Leonard and I turned into the little smoking room assigned to our use, after we had said good night to Rose. Faraday was seated there alone, with a block and pencil in his hand, apparently making idle sketches. He laid the block by his side, face downwards, at our entrance.

"Well," he said, a little ill-naturedly, "I suppose you've seen the treasures?"

"We have," I admitted, helping myself to a whisky and soda.

"Are they as wonderful as report says?" he enquired.

"I'm no judge," I told him, a little shortly.

"By the bye, there's a note for you on the table."

I recognised at once the familiar, typewritten envelope—a message from the chief. Leonard looked over my shoulder as I tore open the envelope:

Watch Faraday. Suspect Edwards, one of the custodians. Registered post to-morrow brings you key of door leading to balcony, end of north gallery.

I tore the note into small pieces. Faraday sat watching me with gloomy curiosity.

"Nothing annoying, I hope?" he queried.

I watched the pieces filter through my fingers into the waste-paper basket.

"Nothing of any importance," I assured him.

The next day several things happened. In the first place, the key of the door leading to the little gallery facing the jewel chamber arrived, wrapped in tissue paper and with an obliterated postmark. Secondly, I took five wickets for fifteen against the team brought over from a neighbouring country house, and Leonard, by indefensible slogging, managed to knock up fifty-five before he was caught on the boundary. These last two episodes seemed to obliterate all memory of the professional character of our stay. The Duke, who had played a very useful innings himself, and whose joy at winning the match was almost like a schoolboy's, treated us as honoured guests and insisted upon all three of us accepting his invitation to dine in the great hall that evening. The third event of the day was the coming of the Princess Anne of Chantilly, the last representative of a famous French family, a great heiress, related to royalty, and one of the beauties of the world. The three of us chanced to witness her arrival, and our host's secret was manifest in the first few minutes. In her presence he seemed rejuvenated. He watched her every movement. The slight austerity of his tone and deportment vanished as though by magic. A new and more genial side of him appeared. He paid his court almost openly. It did not need the gossip of the place to tell us that he was her suitor.

I was ready for dinner early that evening and strolled up and down the north gallery, waiting for Rose, who was naturally taking some pains with her toilette. I made my way as though by accident to the notice board containing the names of the watchmen selected from the menservants of the establishment. There were eleven altogether, and the watch for the next twenty-four hours had just been put in. For the first time I saw there the name of Edwards. He was on duty, it seemed, from three to six on the following morning. I felt a little shiver of excitement as I strolled away, after a surreptitious glance at the little gallery. The beginning of my task was close at hand.

Dinner that night was a pageant rather than a meal. Sixty-four of us sat down at a long table, the decoration of which with hothouse flowers had taken two gardeners the greater part of the day. We were served from gold plate and we drank strange wines from Venetian glasses. The Duke sat at one end of the table, with the Princess at his right hand, and his sister, the Marchioness of Leicestershire, sat at the other end. The Princess, of whom I had a good view, was one of the most beautiful women I had ever seen. She was fair and slim, with a perfect complexion, dark, rather tired eyes, a fascinating mouth, and corn-coloured hair, whose seemingly simple arrangement was an artistic triumph. The one remarkable thing about her, though, was that she wore not a single article of jewellery. Her neck and bosom were bare, her fingers were ringless. I ventured to remark upon this fact to my neighbour, whose acquaintance I had made on the cricket field. She glanced down the table and nodded.

"The Princess has strange fancies," she remarked. "I have seen her wearing the Chantilly emeralds at a small dinner party, and afterwards go to a Court function wearing the jewels of an ingÉnue."

I looked back at her with a very genuine admiration.

"She ought to marry the Duke," I whispered, "if only for the sake of wearing the wonderful pink pearls."

My companion smiled.

"She would look better in them than any woman in the world," she agreed. "The pity of it is that she would only be able to wear them up here, and for a woman of her cosmopolitan tastes, Westmoreland would seem a little confining.""But if she were Duchess of Lorringham?"

My companion shook her head.

"The jewels are a very solemn family trust," she told me. "I believe I am right in saying that they cannot be taken out of the United Kingdom. One of the famous tiaras was stolen about a hundred years ago in London, and the deed of trust was amended then. I suppose it is quite all right," she went on meditatively, "but in a way it seems a cruel thing to keep jewels of such value practically hidden."

We gave our little entertainment that evening, after which a great pianist who had travelled down from London gave a recital, Faraday made more magic, and a girl, who was one of the house party, danced. All the time our host never left the Princess's side. There was no doubt at all but that he was deeply in love with her. She, for her part, won all hearts. She was gracious and charming to every one. She seemed, indeed, to the Duke's delight, to almost assume at times the position of gracious chatelaine. A thought came to me during the evening and I sought out young Formby, with whom Leonard and I had become quite intimate. I found him with some of the younger spirits in the billiard room. I drew him on one side whilst he was waiting to play his shot at pool.

"Formby," I said, "I don't want to seem impertinent but I should like to ask you a question."

"Go ahead," the young man invited.

"Is the Duke a rich man?" I asked.

Formby looked at me in astonishment.

"What on earth makes you ask a question like that?" he demanded curiously.

"Well, I really haven't any reason," I hastened to assure him. "I just wondered, that's all."

"The Duke," he told me impressively, "is one of the richest men in England. He spends money in a princely fashion but he has never yet succeeded in spending half his income. What about a game of snooker—you and Cotton, too, if he likes? We are breaking up after this. Sir Charles wants to dance."

I left Cotton there and went in search of Rose. I found her on the balcony in our own sitting room, looking down at the guests—strange, picturesque figures as they strolled about the moon-dappled lawn, listening to the music.

"Maurice," she asked me, as I sank into a chair by her side, "have you found out yet what we are here for?"

"I haven't the faintest idea," I replied. "The chief has been even less communicative than usual. It seems to have something to do with the jewels and that is all I know."

"You don't think," she went on nervously, "that by any chance we are sent here to aid in any attempt to steal them?"

"No, I don't think that," I assured her. "Where the chief stands sometimes I can't quite make up my mind, but I don't think a jewel robbery, even on such a scale as this, is quite in his line. If our presence here has anything to do with jewels at all, and I think it has," I added, dropping my voice, "I should say that we were here indirectly to aid their guardians."

"Then why doesn't the Duke mention it to us?" she asked curiously."It's beyond me," I confessed.

She laid her hand upon my arm and drew me very near indeed.

"Maurice," she whispered, "there's something wrong about Faraday."

"Go on," I begged her.

"Well, for one thing, then, what does he want with a ninety horse-power car, concerning which he hasn't said a word to any of us? I saw him driving it in the lower stretches of the park this morning."

"Well, that might be any man's hobby," I replied. "What else?"

"I found him poring over a map this afternoon," she continued. "I looked over his shoulder. It was a road map of Westmoreland, and I am perfectly certain that he was tracing out the road from here to the sea. It is only twenty miles."

I nodded.

"Well," I said, "let us assume, then, that Faraday means to make an attempt to steal the jewels, that he has a high-powered car in readiness, and a boat of some sort waiting by the sea. I dare say that part of it might be managed all right. It's a desolate coast, the road to it lies over a mountain range, and he could easily start from a place where there is no telephone or telegraph. But—it's the robbery itself that seems to me so impossible. I can't conceive how any one could get at the Duke's key, and, having got it, how they could pass the man on duty at the door, to say nothing of leaving the Castle afterwards."

"Most robberies seem like that until afterwards," Rose answered, a little drily.

"Besides," I argued, "Faraday is, in his way, a famous man. He must earn several thousands a year. Why should he run such appalling risks?"

"Go and look at the Era, which I left on the sitting-room table," she enjoined. "Look at the paragraph at the bottom of the sixth page."

I obeyed her, and read with a little start of surprise of the great deception accorded to Faraday at Melbourne the previous week.

"What does it mean?" I asked Rose, when I returned.

"It means that this man isn't Faraday at all," she declared. "I was doubtful of him from the first. I saw Faraday at the Coliseum about two years ago, and I am sure that he was a much older man."

"In that case," I said thoughtfully, "I suppose it is our duty to warn the Duke."

"You must do as you think best," Rose decided.

I made my way reluctantly downstairs and turned into the gardens where I was told the Duke was. I found him at the end of a rose pergola. The Princess was seated by his side, and at the sound of their voices I hesitated and would have turned back. The Duke, however, recognised me and called out. In the bright moonlight which was flooding the gardens, he seemed unnaturally pale. His tone, too, when he addressed me, had lost its smooth, pleasant intonation. He was like a man who has been undergoing torture. The slight smile upon the Princess's lips chilled and depressed me. I felt that it was not a pleasant interview which I had disturbed.

"Were you looking for me, Lister?" the Duke asked."In a sense I was, your Grace," I admitted. "I—er—there was a little matter I thought I ought to mention to you."

"Well?"

I felt suddenly that my mission was ridiculous and my suspicions intolerable. Since I was there, however, I had to go through with it.

"The man Faraday, the illusionist," I began——

"Well, what about him?" the Duke interrupted sharply.

"Some one who saw Faraday perform at the Coliseum two years ago," I continued, "is of opinion that this man is not Faraday at all. The suspicion is confirmed by the fact that, according to this week's Era, Faraday is performing in Melbourne."

"I have no doubt that your information is correct," the Duke replied coldly. "Now I come to think of it, I believe the agents told me that they were sending a Faraday man but not Faraday himself. You surely had some reason for bringing me this—information?"

The wild absurdity of the whole thing made me feel like a fool. Then I remembered, however, that we had been deliberately sent here by our Machiavellian chief, and we had never been sent anywhere in vain.

"It must sound idiotic, your Grace," I confessed, "but we were all very much impressed by the precautions against robbery connected with your jewel chamber. The fact that there was a man staying here to whom you yourself preferred not to show the jewels—staying here under a false name, with a ninety horse-power motor car in the garage——"

The Duke interrupted me with a slight exclamation and a little wave of the hand.

"I never dreamed that you were such an old woman, Lister," he said. "I am much obliged to you for your warning," he added, with some return of his old courtesy. "As it happens, however, I was already aware that this man was not Faraday himself, and I fancy that my precautions for guarding the Lorringham treasures are adequate."

The Princess leaned a little forward. I sympathised with the Duke. In this faint, enchanting light, she was ravishingly beautiful.

"Do not be too confident, dear host," she murmured. "If women were only made of sterner stuff, a lock has never been fashioned which could keep a pearl lover from your jewel chamber."

The Duke smiled.

"Nevertheless," he added, turning to me with a friendly gesture of dismissal, "you may sleep soundly to-night and as many nights as you remain under my roof. The spells are not yet woven which could charm those jewels from their cases."

I made my way back to the Castle, a little confused. There seemed to be in the Duke's last words a subtle behest to me, a warning not to concern myself further in his affairs. And from three to six on this coming morning, Edwards was guard of the chamber, and my rÔle of watcher was already established.

It must have been within a few seconds of the chiming of a quarter past three, that the intense silence of the gallery, into which I had found my way without difficulty, was broken in even the slightest degree. Opposite where I crouched, in a high-backed chair, with a glass of cold water by his side, sat the custodian of the jewel chamber. A little to the right was the narrow passage leading to the Duke's apartments. Two electric lights were burning, and through one of the windows came pale splashes of faint moonlight. The effect was a weird and confusing illumination which made it hard to recognise even the simplest objects. The armoured figures cast fantastic shadows across the floor, the outline of the watching man seemed distorted and unreal, and the whole setting of the little scene was unnatural, a stimulus to nervous imagination. For this very reason I covered my eyes and looked again for a moment at the apparition which at first presented every semblance of the impossible. The second time I knew that I had not been deceived—I knew that something was happening.

The end of that little passage leading from the Duke's apartments to the watching figure was wrapped in gloom. The faint creaking which had first attracted my attention might have come from an unseen door there, or it might have been the not unnatural creaking of timbers in an old house. The sound, however, was followed by a strange vision. I saw an arm stretched out from the shadows, linger for a moment over the tumbler, and then disappear. I rubbed my eyes. Was this Faraday and his toy magic, or reality? I waited. It might have been ten minutes before the next happening. The watcher in the chair stretched out his arm, lifted the tumbler to his lips and drank. After that there was silence again. Then from the spot where the arm had come, a figure dressed in black stole out, the figure of a man of medium height, without betraying collar or shirt front, black as a bat save for the pale blur of an indistinguishable face, and noiseless. He stooped over the custodian, now evidently either asleep or unconscious. In a moment or two he stood upright, paused before the door of the jewel chamber, and with a curious, apparently effortless movement, passed through it. Then it seemed to me that my time had come for action. I stole quietly down the few stairs, unfastened the door of the gallery, and crept up the corridor. The door of the jewel chamber was ajar, and through it I could see the shining of the electric light inside, a glimmer of which fell upon the face of the drugged custodian. Suddenly, upon the very threshold of the jewel chamber, I stopped short. All my wariness was gone, lost in a shock of surprise. A little exclamation broke from my lips. The next second I found myself struggling for my life. The walls swam round. I raised my voice and gave a great cry. After that there was silence.

At twelve o'clock the next morning, with a bandage around my head, and feeling still the effects of an almost delirious night, I stepped into the car which was waiting to take us to the station. The Duke, who was practising at the cricket nets, came hurrying across to us, his bat still in his hand.

"I had no idea that you were going by this early train!" he exclaimed. "So glad that I did not miss you altogether."

Rose murmured something polite, and Leonard said a word or two about the pleasure of our stay. I remained silent."I am afraid," our host continued, smiling at me, "that I was a little unsympathetic in the small hours of the morning. I am never at my best when I am roused from sleep. However, you must let me express my regrets to you now, Mr. Lister, for your little accident. At the same time," he went on, "I am sure you will agree with me that the neighbourhood of the jewel chamber is rather a dangerous place for a man addicted to nightmares to be wandering about at three o'clock in the morning."

I looked the Duke in the face.

"What I saw was no nightmare," I said. "I saw some sort of powder dropped into Edwards' glass, and I saw a man pass into the jewel chamber."

The Duke smiled tolerantly.

"My dear Mr. Lister," he protested, "if the man Edwards had been drugged as you suggest, could he have attacked you in the way he did and got the better of you in a scrap? Further, how was it possible for any one to open the door of the jewel chamber without a key?"He rolled up the sleeve of his flannel shirt a little higher, touched the spring of his platinum bracelet, showed us the key and replaced it. I said nothing. I continued to watch the Duke's face.

"Perhaps the most satisfactory part of your hallucination," he went on, "is the fact that the jewels have neither been disturbed nor removed. I beg, Mr. Lister," he concluded indulgently, "that you will not let this unfortunate incident disturb any agreeable impressions you may have had of your stay here. It has been a great pleasure to me to entertain you. If you will allow me to refer for a moment to a business matter, my steward has sent a cheque this morning to your agent. And if you will allow me to offer you a slight memento of your stay here, I will ask you to accept this bat from me. It is one of Wisden's, and I think the best I have ever handled."

He held it out to me, and there passed between us one of those long and silent glances which convey more than words. I held out my hand and accepted the bat."Thank you, Duke," I said.

He stood away and lifted his cap. Then we drove off.

Mr. Thomson had his own methods of surprising us. Three nights after our return to town, we found ourselves, for instance, under the great plane tree at Ranelagh, drinking wonderful yellow chartreuse with our coffee, listening to the music and to the little murmur of pleasant, after-dinner conversation. The moment for which I had waited so eagerly had come at last.

"On this occasion," our host remarked tolerantly, "I feel that I must be a little more lenient than usual as regards questions. You came away from Lorringham a little puzzled, I have no doubt?"

"We did indeed," I replied. "We want to know why the Duke was engaged in a conspiracy to steal his own jewels, and why our mission there seemed to be to prevent it."

"Quite a little romance," our host observed. "The Duke, as you may have noticed, is very much in love with the Princess of Chantilly. The Princess is one of those women in whom the love of jewels amounts to a passion. The Lorringham pink pearls are, as you may know, priceless. More than anything in the world the Princess desires to wear those pearls."

"Then why doesn't she acquire them by marrying the Duke?" I asked.

"Because," Mr. Thomson explained, "in the trust deed relating to the jewels they can none of them be moved outside the United Kingdom. The Princess would never live in England for more than a month or so in the year, which means that she would be separated from the jewels she loves for the greater part of the time. The Duke has taken every sort of legal opinion, and there is no doubt that if they were stolen from the Castle and returned to him in some foreign country, there is no law which could compel him to bring them back here. That is why the Duke connived at the theft, which you prevented."

The elucidation was simple enough but scarcely satisfactory.

"If I had known this," I confessed, "I'm afraid my sympathies would have been with the Duke."

Mr. Thomson smiled indulgently.

"That proves, then," he said, "how wise I am to explain these little affairs with which you chance to become associated, afterwards instead of before. You were acting for the insurance companies, who would have to pay a very large sum to the vested estate if the jewels were stolen from Lorringham. On their behalf," he added, handing me an oblong strip of paper, "I am asked to hand you this cheque for five hundred pounds."

I passed it over to Leonard, who usually kept our accounts.

"All the same," I observed, "I don't wonder the Duke thought I was a meddlesome idiot."

"His Grace has probably forgiven you," Mr. Thomson remarked, "for the Princess has relented at last. If you buy an evening paper on your way home, you will see that they were married by special license this afternoon."

We found plenty to think and talk about for the next few minutes. Then Mr. Thomson, who had been leaning back in his chair, watching the stars and listening to the music, electrified us.

"In one month," he said, "the year for which you pledged your services to me will be up. At the end of that time we shall say good-by."

"You will not want us again?" Rose asked.

Mr. Thomson shook his head.

"Please do not consider that any reflection upon your efforts," he begged. "During the last ten years I have had assistants in every walk of life. No one has served me more intelligently or on the whole more successfully than you three. The fact of the matter is that I am going to retire."

"Retire from what?" I asked him impetuously. "Who are you? What are you? I have never been able to make up my mind whether we have been on the side of the sheep or the goats. How did you become interested, for instance, in this last affair? Did the insurance companies give you a brief? And if so, did they give it to a master criminal, to police headquarters, or to a private detective?""Shall we call that Conundrum Number Six?" Mr. Thomson suggested, watching the ash on his cigar. "You understand, of course, that we are going to have a grand finale. You have a week in which to rest, and I think a study of your banking account will prove that you are justified in taking a holiday if you wish to. On next Thursday evening, at six o'clock, I desire that all three of you will be at the rooms which you are now occupying in Clarges Street. You will there receive a message from me. I shall ask your help once more before I retire into private life—and safety."

The music surged in our ears, and the froth of light conversation filled the air. Of all the little groups of people seated about, we alone seemed to have our faces set towards the serious things. Perhaps our host noticed it, for he rose to his feet and drew Leonard on one side.

"If I were your age, Lister," he said, turning to me, "I should ask Miss Mindel to drift about with me in one of those shadowy boats."

So Rose and I strolled down towards the lake."To think," she murmured, a little tremulously, "that very soon we shall come to the end of our adventures!"

I drew her arm through mine. The sound of the music was growing fainter in the distance and the ripple of the water was in our ears.

"Or to the beginning," I whispered.