Miss Jenrys went faithfully to the post-office in the Government Building the day after our visit to Midway, and the next, and the next. On the fourth day she was rewarded, and when I appeared at her door, as I did every day now, by appointment, and at a fixed hour, she put a square envelope into my hand. It was addressed to 'J. J., World's Fair P.O.,' and the seal was unbroken.

I looked at the initials in surprise. 'Is it possible,' I asked, 'that you two have not exchanged names? Has it always been J. J. and H. A.?'

'Quite so,' she laughed. 'It was her proposal. It would keep up the romance of the acquaintance, she said,' and as I held out the envelope toward her, 'No, that is your letter; I have no interest in it, and little curiosity concerning it.'

'Then,' said I, as I broke the seal, 'I shall read it to you because of that little.'

But when I had unfolded the sheet, I sat so long staring at it that she asked lightly: 'Does it contain a scent, after all?' I put the letter in her hand. 'Read for yourself,' I said, trying to speak carelessly; and she read aloud:

'"H. A.'

'Bah!' She tossed the letter back to me with a little disdainful laugh. 'It reads like a love-letter, and is anything but filial.' As I folded the letter and put it carefully away, she watched me keenly.

'Mr. Masters,' she said, 'you have been in some unaccountable manner startled, or shocked, by that letter.'

I could neither deny nor explain, and I frankly admitted it, assuring her that she would not remain long in the dark.

'Oh, I can wait,' she smiled. 'Do not fancy me so unreasonable as to expect the full confidence of a detective. Only, don't fear for my "nerves," and let me help in any way that I can. I think,' laughing, 'that I have said this before.'

I was anxious to go now, and, rising, I took her at her word. 'You can help me in two ways,' I said, 'but I must ask you not to demand reasons just yet.'

'Go on,' she said promptly.

'First, should this brunette, this "H. A.," write you again, will you inform me at once, and—I don't think it likely to occur, but if she should call here, will you refuse to receive her?'

'Yes to both. But she does not know my address.'

'You forget; she has been seen to pass this house. Don't be too sure.'

'I will be on my guard. Is that all?'

'There is another point—a delicate one. I could not but see that Monsieur Voisin's company that day in Midway was not entirely welcome to your aunt and yourself; and—bear with me, please, I am speaking in the interest of another. Promise me that you will not close your doors against Monsieur Voisin, or treat him too coldly, for a little while. Believe me, my reason is one that you will be first to endorse when it is known to you.'

She hesitated, and I hurried on:

'The man is of a fiery disposition, and he recognises a rival in the field—pardon my intrusion upon delicate ground. He comes from the land of duellists.' She started. 'A little patience and diplomacy upon your part, and I think I can promise that he will not annoy you much longer.'

'Very well,' she assented, 'I agree. Auntie, strange to say, has urged the same thing—concerning Monsieur Voisin, that is. At the worst we can go home. It is now the last of June, and we go, in any case, in July. Never fear, I shall not forget your admonitions, any of them.' And she gave me her hand at the door with a reassuring smile.

Half-way over the threshold I turned back to say: 'By the way, Miss Jenrys, if I chance to appear here at the same time as Monsieur Voisin, please be kind to me.'

Late that same night Dave Brainerd and I held one of our long, and, in the past, ofttimes useless and mistaken, symposiums. But this time we were in perfect accord. We had spread upon the table before us our old memoranda from the very beginning of our campaign, and also some few letters and other documents. It had been a long 'session,' according to Dave, but the conclusion was so satisfactory that, at the last, we had each lighted a cigar, and celebrated thus what we considered a fully mapped out campaign at last.

'Well,' pronounced Dave, with a sigh of content, as he tipped back his chair, and elevated his feet to the top of the table between us. 'This looks like business! Let us see! First,' checking off on his fingers, 'we're to keep away from Midway—all but Billy—so that they may not make another flitting, eh?'

'Yes,' I assented.

'And we're to patrol Stony Island Avenue and the surrounding country by day and by night, with a full force. Ain't that it?'

'Perfectly. Dave, you are as full of repetitions as an old woman!'

'Or a young one,' he retorted; 'and you think it is proved that the brunette's a man, do you?'

'It was proved, for me, long ago.'

'And that letter? I can't see why it should not be launched at once.'

I had written to Mr. Trent, telling him of certain facts and theories, and among them was the suggestion that we should cause a copy of the 'Roe' letter, with its proposed barter, to be published in the morning papers, giving him my reasons at length, and requesting his opinion before taking what might prove a very decisive if not aggressive step. Dave was delighted with this idea, and, wearied with our 'masterly inactivity,' he would, as he put it, 'launch the thing at once.' My reasons, as explained to both Dave and Mr. Trent, were:

The letter signed 'Roe,' and offering to liberate young Trent, and at the same time to defraud the comrades of the 'clique,' if genuine, would, when published, expose the writer, who would then be obliged to 'leave the clique,' as he had expressed it, and with an additional 'reason' for so doing; this would at least lessen their numbers, and perhaps force them to take into their confidence some new colleague. Or, possibly, it would result in a quarrel among themselves, which also might result in some way in our favour.

On the other hand, if it were a scheme of the clique, it would seem that at least they were tired of the game and in need of money; and the advertised letter, if followed up by another advertisement—in which a correspondence might be proposed or some proffer made—might draw them out; and in some way this must be done. In the meantime a warrant must be issued, or rather two, one descriptive of the brunette as a woman, the other as a man; and since the Lausch people had not done so, we would, if we could, arrest her or him on the charge of robbery.

I had to go over the ground once more to quiet Dave, or to tire him out; and we ended at last, as usual, in mutual agreement.

Several days must pass, I knew, before Mr. Trent would arrive. I had written him daily, and he had replied by telegraph. He would be with me soon, and would wire me the date of his arrival. In the meanwhile I was to 'act upon my best judgment' in the matter of delaying the advertisement. I decided to wait and watch, and so a few more days passed in routine and quiet.

On one of these quiet days Lossing and I, in a moment of leisure, went down to that interesting, and by many neglected, portion of the Exposition grounds where are situated the cliff-dwellers; the Krupp gun, giant of its kind; the Department of Ethnology, and the great Stock Pavilion, where the English military tournaments were held afternoons and evenings. It seemed to be by mutual consent that we turned away from the little point of land where La Rabida sat isolated, as a convent should; and, crossing the bridge that spanned the inlet between the convent and the stately Agricultural Building, we passed through its spacious central promenade and, passing by the Obelisk and under the Colonnade, paused at the military encampment.

There was no performance at that hour, but men and horses were being led into the monster pavilion, 'for exercise,' a big trooper explained to us, 'and a bit of drill for the 'orses.' At which Lossing slipped his hand through my arm. 'Come on,' he said, and, a little to my surprise, he led me to a side door, and taking a card from his pocket, held it an instant before the eyes of the soldier on guard, saying a word as he passed him, which I did not catch.

As we entered the great inclosure, a group of officers were standing near the centre of the arena, in busy converse, and a heavy artillery team was being put through its paces, while nearer our place of observation several cavalrymen were leading their horses up and down. The officers evidently were discussing and arranging some matter of importance. But while I noted this, I also noted that one of them who stood facing toward us lifted his hand in salute, and then moved it toward us in a less formal gesture, and, again to my surprise, my companion lifted his hand and returned the salute in kind. Before he could look at me I had turned my eyes away and was watching with evident interest the manoeuvres of the cavalrymen.

They had mounted their animals and were beginning to put them through their paces, and presently they began the drill known as throwing their horses.

Galloping the animals to a certain point, they were brought to a short and sudden stand, and then by a quick tug upon the bit, the animal, if well trained, allowed itself to fall upon one side, the rider instantly slipping from the saddle to a position half concealed by the body of the horse from an imaginary enemy in front, and gun in hand, ready to take aim across the saddle.

There was one man who did not at first go through this evolution with the others, but set his horse near the rest looking on. When the others had gone through the exercise, this man rode forward, put his horse at a gallop, stopped him splendidly, and attempted the fall; but the animal was obstinate or only half broken, and began to show signs of both fright and fight.

As his rider turned the excited creature about, and sent him at a mad gallop across the arena, one of the troopers came at an easy trot directly toward us, and drawing rein beside us, with a lift of his hat, said respectfully:

'Good-morning, sir. I hope you are well, sir.'

'Good-morning, George,' replied Lossing easily. 'What is the matter with that horse?'

''E's a new one, sir, and not quite broke; though I do think, sir, as he 'asn't the best and kindest of riders, sir, and that makes 'im worse.'

'Yes,' said Lossing absently, with his eyes following the horse, which was a really fine animal, one to attract a horse-lover.

'Hit's too bad,' went on the trooper. 'Diggs will 'ave to ride 'im this hafternoon, and it'll bait the cap'n horful; for one of our 'orses come a fluke last hevenin'. I be sorry for Diggs!'

'I'm sorry for the horse! George, go and ask the captain to send Diggs and his horse to me.'

No doubt my face showed my surprise as the trooper rode obediently off to do his bidding; but Lossing only smiled and moved a step or two away from the rail where we had been standing.

'Diggs,' he said, as the man rode up and saluted. 'Will you let me try your horse?'

The soldier saluted again, and dismounted without a word; and Lossing took the bridle from his hand, and for a few moments stood beside the horse, stroking him, smoothing his mane, and all the time speaking some low, soothing syllables that seemed to quiet the still quivering animal.

After a little of this he examined the saddle, adjusted the stirrups and bridle, and then, after leading the horse away from us a short distance, he stepped easily and quietly into the saddle. Instantly the creature's head was erected, and his ears put back, but Lossing, with a caressing hand upon his neck, continued his low, soothing syllables, and let the animal walk the length of the long inclosure.

Turning then, he sent him back at a gentle trot, which he increased gradually, until he was careering around the arena in circles, which became shorter and shorter, until he came to a halt in the centre of the vast place. Then after a few more gentle words and light pats upon the sleek neck, he bent over and suddenly drew the rein. Once, twice, three times he gave that sharp pull, but the horse stood steadfast. Turning in his saddle, he said something to the troopers who had drawn near him, and then sat erect in his place, while three of the troopers turned their horses and went careering around the motionless horse and rider. Soon, at another word from Lossing, one of the men rode alongside, while the others drew back.

When the trooper had ranged himself at the side of Lossing's horse and only a few feet away, Lossing nodded; and at the first tug at the rein the trooper's well-trained animal went down and lay supine and moveless.

Then Lossing beckoned a second time, and as the fallen horse got up he was caressed by Lossing, who leaned from his saddle to reach him, and then led away, as the second trooper came up leading his horse.

As the animals stood side by side Lossing dismounted, stood a moment beside his refractory steed, and then, with a gentle pat and a low word as if of reproof, he turned and, after patting the other animal a moment, sprang to its back and sent it galloping around the place; then bringing him back to place, and with a pat or two and a quick 'Now down!' threw him, sprang to his feet, and before the animal could rise had again mounted the wayward horse.

Once more he trotted slowly away, caressing and talking to the horse; and then, suddenly wheeling him, he gave a cheery command and sent the creature flying back, past his old place, and across the pavilion; then turning and halting the horse before the group of officers, he gave him a brisk pat, and said cheerily, 'Now down!' and, almost with the word, the creature threw up its head and, with scarcely an instant's hesitation, went over and lay quivering upon the ground.

A cheer went up from the onlookers. But without loss of time Lossing had the horse up, turned him about, and, seeing him quite fit and not too nervous, remounted; and now the horse was obedient to his every move or word. Twice more he threw him, and then, returning him to Diggs, he said:

'Diggs, a horse can be as jealous as a woman, and more easily shamed than a boy. And if you are skilful, and love your horse, you can master him; but beware of the first angry word. Anger makes brutes; it never made an intelligent animal yet.'

He took my arm, and with a bow and a shake of the head to the officers, who were moving toward him, and a nod to the troopers, he hurried me out of the pavilion.