On this same Christmas Day Sergeant Hooper was feeling morose and discontented; not because he was alone in the world (a situation comprising many advantages); nor on the score of his wages, which were extremely liberal; nor on account of the "old blighter's"—that is, Mr. Saffron's—occasional outbursts of temper, these being in the nature of the case and within the terms of the contract; nor, finally, by reason of Beaumaroy's airy insolence, since from his youth up the Sergeant was hardened to unfavourable comments on his personal appearance, trifling vulgarities which a man of sense could afford to ignore.

No; the winter of his discontent—a bitter winter—was due to the conviction, which had been growing in his mind for some time, that he was only in half the secret, and that not the more profitable half. He knew that the old blighter had to be humoured in certain small ways—as, for example, in regard to the combination knife-and-fork—and the reason for it. But, first, he did not know what happened inside the Tower; he had never seen the inside of it; the door was always locked; he was never invited to accompany his masters when they repaired thither by day, and he was not on the premises by night. And, secondly, he did not understand the Wednesday journeys to London, and he had never seen the inside of Beaumaroy's brown bag—that, like the Tower door, was always locked. He had handled it once, just before the pair set out for London one Wednesday. Beaumaroy, a careless man sometimes, in spite of the cunning which Dr. Irechester attributed to him, had left it on the parlour table while he helped Mr. Saffron on with his coat in the passage, and the Sergeant had swiftly and surreptitiously lifted it up. It was very light—obviously empty, or, at all events, holding only feather-weight contents. He had never got near it when it came back from town; then it always went straight into the Tower and had the key turned on it forthwith.

But the Sergeant, although slow-witted as well as ugly, had had his experiences; he had carried weights both in the army and in other institutions which are officially described as His Majesty's, and had seen other men carry them too. From the set of Beaumaroy's figure as he arrived home on at least two occasions with the brown bag, and from the way in which he handled it, the Sergeant confidently drew the conclusion that it was of a considerable, almost a grievous, weight. What was the heavy thing in it? What became of that thing after it was taken into the Tower? To whose use or profit did it, or was it to, ensure? Because it was plain, even to the meanest capacity, that the contents of the bag had a value in the eyes of the two men who went to London for them, and who shepherded them from London to the custody of the Tower.

These thoughts filled and racked his brain as he sat drinking rum and water in the bar of the Green Man on Christmas evening; a solitary man, mixing little with the people of the village, he sat apart at a small table in the corner, musing within himself, yet idly watching the company—villagers, a few friends from London and elsewhere, some soldiers and their ladies. Besides these, a tall slim man stood leaning against the bar, at the far end of it, talking to Bill Smithers, the landlord, and sipping a whisky-and-soda between pulls at his cigar. He wore a neat dark overcoat, brown shoes, and a bowler hat rather on one side; his appearance was, in fact, genteel, though his air was a trifle raffish. In age he seemed about forty. The Sergeant had never seen him before, and therefore favoured him with a glance of special attention.

Oddly enough, the gentlemanly stranger seemed to reciprocate the Sergeant's interest; he gave him quite a long glance. Then he finished his whisky-and-soda, spoke a word to Bill Smithers, and lounged across the room to where the Sergeant sat.

"It's poor work drinking alone on Christmas night," he observed. "May I join you? I've ordered a little something; and—well, we needn't bother about offering a gentleman a glass to-night."

The Sergeant eyed him with apparent disfavour—as, indeed, he did everybody who approached him—but a nod of his head accorded the desired permission. Smithers came across with a bottle of brandy and glasses. "Good stuff!" said the stranger, as he sat down, filled the glasses, and drank his off. "The best thing to top up with, believe me!"

The Sergeant, in turn, drained his glass, maintaining, however, his aloofness of demeanour. "What's up?" he growled.

"What's in the brown bag?" asked the stranger lightly and urbanely.

The Sergeant did not start; he was too old a hand for that; but his small gimlet eyes searched his new acquaintance's face very keenly. "You know a lot!"

"More than you do in some directions, less in others perhaps. Shall I begin? Because we've got to confide in one another, Sergeant. A little story of what two gentlemen do in London on Wednesdays, and of what they carry home in a brown leather bag? Would that interest you? Oh, that stuff in the brown leather bag! Hard to come by now, isn't it? But they know where there's still some—and so do I, to remark it incidentally. There were actually some people, Sergeant Hooper, who distrusted the righteousness of the British Cause—which is to say" (the stranger smiled cynically) "the certainty of our licking the Germans—and they hoarded it, the villains!"

Sergeant Hooper stretched out his hand towards the bottle. "Allow me!" said the stranger politely. "I observe that your hand trembles a little."

It did. The Sergeant was excited. The stranger seemed to be touching on a subject which always excited the Sergeant—to the point of hands trembling, twitching, and itching.

"Have to pay for it too! Thirty bob in curl-twisters for every ruddy disc; that's the figure now, or thereabouts. What do they want to do it for? What's your governors' game? Who, in short, is going to get off with it?"

"What is it they does—the old blighter and Boomery" (Thus he pronounced the name Beaumaroy)—"in London?"

"First to the stockbroker's—then to a bank or two—I've known it three even; then a taxi down East, and a call at certain addresses. The bag's with 'em, Sergeant, and at each call it gets heavier. I've seen it swell, so to speak."

"Who in hell are you?" the Sergeant grunted huskily.

"Names later—after the usual guarantees of good faith."

The whole conversation, carried on in low tones, had passed under cover of noisy mirth, snatches of song, banter, and giggling; nobody paid heed to the two men talking in a corner. Yet the stranger lowered his voice to a whisper, as he added:

"From me to you fifty quid on account; from you to me just a sight of the place where they put it."

Sergeant Hooper drank, smoked, and pondered. The stranger showed the edge of a roll of notes, protruding it from his breast-pocket. The Sergeant nodded—he understood that part. But there was much that he did not understand. "It fair beats me what the blazes they're doing it for," he broke out.

"Whose money would it be?"

"The old blighter's, o' course. Boomery's stony, except for his screw." He looked hard at the gentlemanly stranger, and a slow smile came on his lips. "That's your idea, is it, mister?"

"Gentleman's old—looks frail—might go off suddenly. What then? Friends turn up—always do when you're dead, you know. Well, what of it? Less money in the funds than was reckoned; dear old gentleman doesn't cut up as well as they hoped! And meanwhile our friend B——! Does it dawn on you at all—from our friend B——'s point of view, Sergeant? I may be wrong, but that's my provisional conjecture. The question remains how he's got the old gent into the game, doesn't it?"

Precisely the point to which the Sergeant's mind also had turned! The knowledge which he possessed—that half of the secret—and which his companion did not, might be very material to a solution of the problem; the Sergeant did not mean to share it prematurely, or without necessity, or for nothing. But surely it had a bearing on the case? Dull-witted as he was, the Sergeant seemed to catch a glimmer of light, and mentally groped towards it.

"Well, we can't sit here all night," said the stranger in good-humoured impatience. "I've a train to catch."

"There's no train up from here to-night."

"There is from Sprotsfield. I shall walk over."

The Sergeant smiled. "Oh, if you're walking to Sprotsfield, I'll put you on your way. If anybody was to see us—Boomery, for instance—he couldn't complain of my seeing an old pal on his way on Christmas night. No 'arm in that; no look of prowling, or spying, or such-like! And you are an old pal, ain't you?"

"Certainly; your old pal—let me see—your old pal Percy Bennett."

"As it might be, or as it might not. What about the——?" He pointed to Percy Bennett's breast-pocket.

"I'll give it you outside. You don't want me to be seen handing it over in here, do you?"

The Sergeant had one more question to ask. "About 'ow much d'ye reckon there might be by now?"

"How often have they been to London? Because they don't come to see my friends every time, I fancy."

"Must 'ave been six or seven times by now. The game began soon after Boomery and I came 'ere."

"Then, quite roughly—quite a shot—from what I know of the deals we—my friends, I mean—did with them, and reasoning from that, there might be a matter of seven or eight thousand pounds."

The Sergeant whistled softly, rose, and led the way to the door. The gentlemanly stranger paused at the bar to pay for the brandy, and after bidding the landlord a civil good evening, with the compliments of the season, followed the Sergeant into the village street.

Fifteen minutes' brisk walk brought them to Hinton Avenue. At the end of it they passed Doctor Mary's house; the drawing-room curtains were not drawn; on the blind they saw reflected the shadows of a man and a girl, standing side by side. "Mistletoe, eh?" remarked the stranger. The Sergeant spat on the road; they resumed their way, pursuing the road across the heath.

It was fine, but overclouded and decidedly dark. Every now and then Bennett—to call the stranger by what was almost confessedly a nom de guerre—flashed a powerful electric torch on the roadway. "Don't want to walk into a gorse bush," he explained with a laugh.

"Put it away, you darned fool! We're nearly there."

The stranger obeyed. In another seven or eight minutes there loomed up, on the left hand, the dim outline of Mr. Saffron's abode—the square cottage with the odd round tower annexed.

"There you are!" The Sergeant's voice instinctively kept to a whisper. "That's what you want to see."

"But I can't see it—not so as to get any clear idea."

No lights showed from the cottage, nor, of course, from the Tower; its only window had been, as Mr. Penrose said, boarded up. The wind—there was generally a wind on the heath—stirred the fir trees and the bushes into a soft movement and a faint murmur of sound. A very acute and alert ear might perhaps have caught another sound—footfalls on the road, a good long way behind them. The two spies, or scouts, did not hear them; their attention was elsewhere.

"Probably they're both in bed; it's quite safe to make our examination," said the stranger.

"Yes, I s'pose it is. But look to be ready to douse your glim. Boomery's a nailer at turning up unexpected." The Sergeant seemed rather nervous.

Mr. Bennett was not. He took out his torch, and guided by its light (which, however, he took care not to throw towards the cottage windows) he advanced to the garden gate, the Sergeant following, and took a survey of the premises. It was remarkable that, as the light of the torch beamed out, the faint sound of footfalls on the road behind died away.

"Keep an eye on the windows, and touch my elbow if any light shows. Don't speak." The stranger was at business—his business—now, and his voice became correspondingly business-like. "We won't risk going inside the gate. I can see from here." Indeed he very well could; Tower Cottage stood back no more than twelve or fifteen feet from the road, and the torch was powerful.

For four or five minutes the stranger made his examination. Then he turned off his torch. "Looks easy," he remarked, "but of course there's the garrison." Once more he turned on his light, to look at his watch. "Can't stop now, or I shall miss the train, and I don't want to have to get a bed at Sprotsfield. A strayed reveller on Christmas night might be too well remembered. Got an address?"

"Care of Mrs. Willnough, Laundress, Inkston."

"Right. Good night." With a quick turn he was off along the road to Sprotsfield. The Sergeant saw the gleam of his torch once or twice, receding at quite a surprising pace into the distance. Feeling the wad of notes in his pocket—perhaps to make sure that the whole episode had not been a dream—the Sergeant turned back towards Inkston.

After a couple of minutes, a tall figure emerged from the shelter of a high and thick gorse bush just opposite Tower Cottage, on the other side of the road. Captain Alec Naylor had seen the light of the stranger's torch, and, after four years in France, he was well skilled in the art of noiseless approach. But he felt that, for the moment at least, his brain was less agile than his feet. He had been suddenly wrenched out of one set of thoughts into another profoundly different. It was his shadow, together with Cynthia Walford's, that the Sergeant and the stranger had seen on Doctor Mary's blind. After "walking her home," he had—well, just not proposed to Cynthia, restrained more by those scruples of his than by any ungraciousness on the part of the lady. Even his modesty could not blind him to this fact. He was full of pity, of love, of a man's joyous sense of triumph, half wishing that he had made his proposal, half glad that he had not, just because it, and its radiant promise, could still be dangled in the bright vision of the future. He was in the seventh heaven of romance, and his heaven was higher than that which most men reach; it was built on loftier foundations.

Then came the flash of the torch; the high spirits born of one experience sought an outlet in another. "By Jove, I'll track 'em—like old times!" he murmured, with a low light laugh. And, just for fun, he did it, taking to the heath beside the road, twisting his long body in and out amongst gorse, heather, and bracken, very noiselessly, with wonderful dexterity. The light of the lamp was continuous now; the stranger was making his examination. By it Captain Alec guided his steps; and he arrived behind the tall gorse bush opposite Tower Cottage just in time to hear the Sergeant say, "Mrs. Willnough, Laundress, Inkston," and to witness the parting of the two companions.

There was very little to go upon there. Why should not one friend give another an address? But the examination? Beaumaroy should surely know of that? It might be nothing; but, on the other hand, it might have a meaning. But the men had gone, had obviously parted for the night. Beaumaroy could be told to-morrow; now he himself could go back to his visions—and so homeward, in happiness, to his bed.

Having reached this sensible conclusion, he was about to turn away from the garden gate which he now stood facing, when he heard the house door softly open and as softly shut. The practice of his profession had given him keen eyes in the dark; he discovered Beaumaroy's tall figure stealing very cautiously down the narrow, flagged path. The next instant the light of another torch flashed out, and this time not in the distance, but full in his own face.

"By God, you, Naylor!" Beaumaroy exclaimed in a voice which was low but full of surprise. "I—I—well, it's rather late——"

Alec Naylor was suddenly struck with the element of humour in the situation. He had been playing detective; apparently he was now the suspected!

"Give me time and I'll explain all," he said, smiling under the dazzling rays of the torch.

Beaumaroy glanced round at the house for a second, pursed up his lips into one of the odd little contortions which he sometimes allowed himself, and said, "Well, then, old chap, come in and have a drink, and do it. For I'm hanged if I see why you should stand staring into this garden in the middle of the night! With your opportunities I should be better employed on Christmas evening."

"You really want me to come in?" It was now Captain Alec's voice which expressed surprise.

"Why the devil not?" asked Beaumaroy in a tone of frank but friendly impatience.

He turned and led the way into Tower Cottage. Somehow this invitation to enter was the last thing that Captain Alec had expected.