When the door of the stone grotto in the shrubbery at The Hut was slammed in Enid Mallory's face by "The Bootlace Man" her first sensation was one of relief that the repulsive creature had gone away without maltreating her. This was quickly followed by burning indignation at being locked in, so that her sphere of usefulness was limited to the narrow confines of the mouldy moss-grown chamber. And her anger was in turn succeeded by a humorous appreciation of her plight.

"This is what comes of aiding and abetting father's detective propensities," she laughed, immediately checking her merriment lest it should cause the return of her unsavoury captor.

Now that the door was shut the gloom of the mausoleum-like interior was increased twenty-fold, the meagre light that filtered through the ivy-choked window scarcely showing the walls of her prison. But by degrees her bright young eyes grew more accustomed to the obscurity, and she began to search for means of escape. Having embarked on the venture more or less in a spirit of bravado, and being totally ignorant of the tremendous issues hanging in the balance, she was more concerned to get out of her pother without incurring ridicule than with anything else.

She attached but little importance to the triumphant insolence of Tuke when locking her in. The words he had used suggested that he was acting on his own initiative, and not on specific orders from Mr. Nugent, whose approval he hoped to gain. It was possible that he might meet with reproof instead of praise. But she was aware that there was no love lost between her father and the gentleman on whose property she was an undoubted trespasser, and she was annoyed with herself for having done a silly thing which might make an apology necessary.

"If father has to eat humble pie to Mr. Nugent on my account it will be simply rotten," she murmured. "I wish I could get out of this before that wretched man brings him. If I only could there would be nothing to prove that his story is true, or at worst I could stick it out that it was not me he caught."

But to wish herself out of the grotto was one thing, and to find a means of exit another. The door was of oak, strongly clamped with iron and quite impervious to any battery she could administer. She had her golf clubs with her, and essayed to prise open the lock with her driving iron, but the heavy bolt resisted all her efforts. The window was high out of her reach, and if it had not been it was too small for her to creep through. With tears of vexation in her eyes she had to admit that escape was impracticable. There was nothing for it but to await an ignominious release by way of the door when Nugent should have been apprised of her capture. It was possible, she thought ruefully, that he might pretend he had not been told, and keep her there all night as a punishment for her intrusion.

Having resigned herself to the inevitable, Enid characteristically cast about for means to extract what comfort she could out of her cheerless surroundings. The materials at hand were not very promising, the contents of the grotto consisting of a broken lawn-mower, some empty kegs that had held patent manure, and a few obsolete garden tools. But she now noted, what she had missed before, a bench at the far end, running the whole breadth of the grotto. Upon it lay a lot of matting, such as is used for protecting cucumber frames in frosty weather.

"I'm in luck's way at last," she muttered. "That'll make a ripping sofa on which to take it easy till I'm let out of durance vile."

Suiting the action to the word, she moved one or two of the upper mats more to her liking, and then stretched her lithe young frame luxuriously on the improvised couch. In a moment she was on her feet again, staring in dismay at her hastily vacated nest, while every nerve in her body tingled with apprehension.

Something had moved—"squirmed," she called it afterwards—beneath the mats. Something soft and yielding, horribly suggestive of a human body discomfited by her weight.

But there was no further movement. Relieved of its incubus, the thing that had wriggled its dumb protest had reverted to its previous quiescence, and was as uncannily still as it had been all the time she had been in the grotto. Enid felt that she must do one of two things—either scream at the top of her voice, or fathom the mystery of what, or who, it was that lay concealed.

She was no screamer, so screwing up her lips tightly she chose the second course. A few vigorous tugs sent the mats flying hither and thither, and disclosed a man lying prone upon his face on the wooden seat, flattened out like a gigantic lizard. Enid shrank back a little as the figure rose slowly, uncoiling its cramped limbs and peering and blinking up at her. Intuitively she recoiled further still when she saw the ferocity in the haggard eyes.

But even as she looked the fierceness died out, giving place to an expression of patient sadness. The man, who was clad in a cotton blouse and blue jean trousers, made a half-respectful, half-deprecating gesture.

"Ah, so it is not Louise," he said gently in French. "So much the better for the traitress, and for me, perhaps." Then he added in broken English, "Ma'amselle must not be frighted. I do her no harm. I only poor sailor man from onion ship, come in naice cool place for rest."

On the instant Enid's self-possession returned to her. She remembered what her father had said to Reggie Beauchamp—that the clue to the murder of Levison was probably connected with a French lugger engaged in the onion trade, at present lying at Exmouth. It was on the cards that her adventure was not to turn out so fruitless as she had feared. But the man would require careful handling, for she did not lose sight of the fact that she might be in the presence of a murderer. And she was handicapped by not knowing what were the relations between Travers Nugent and this foreigner.

In coming to a conclusion on the latter point, her inherited powers of deduction came to her aid. She shrewdly reasoned that if the man were well disposed towards the owner of The Hut, he would hardly be lurking in the grounds, hidden under a pile of matting.

"I was not frightened—only startled," she replied pleasantly. "You see I am an intruder here, just as much as I expect you are yourself. I am afraid it will be as awkward for you as for me—my getting myself locked in by that horrid creature."

Pierre Legros laughed grimly. "It no matter to me, so long as the right person come to unlock the door," he said.

The words were suggestive of some sinister purpose—if not of some secret relating to the past. Enid reflected quickly that she must draw this man out if he was to be useful to her in either respect. And it also occurred to her that he might be made useful in more ways than as a source of information.

"You thought I was some one else when I sat down upon you?" she said, ignoring his last remark, and trying to read his features in the gloom. It was light enough to enable her to note that her question recalled the ferocity to his deep-sunk eyes, though not for her. His hardening gaze was rather for some one he saw in his mental vision.

"Yes, I t'ink you was anozer person, ma'amselle, and for that I demand of you the kind pardon, for she very weecked person," he said. "Ma'amselle not cruel and weecked—I Pierre Legros, tell by her voice. But that ozair, she fille du diable, and trample on the heart of man, and make him more bad than herself. She and her false Ingleesh lover."

The onion-seller had no more terrors for Enid, and she drew a little closer, subtly conveying the idea of confidence in order to win his confidence. She rejoiced that she had been locked up in the grotto now. She guessed that the core of the mystery lay under the cotton blouse of this rugged foreign sailor, and she meant to have it out of him by hook or by crook. Rapidly casting about for the most effective weapon in her equipment, she hit upon friendly sympathy as the best—for the opening of the campaign, at any rate. A little later, perhaps, she would play for all it was worth the sentiment that they were companions in the same dilemma.

"I am sorry that you are in trouble," she said kindly, and wondering what language Reggie would use if he knew how he was to be exploited for her purpose. "I wish I could help you, for I, too, know what it is to have an affair of the heart. I am betrothed to a sailor, and he has gone away and left me miserable. Got half a dozen wives in half a dozen ports, I expect."

Enid Mallory was her father's daughter, and had inherited a strain of the veteran diplomatist's knowledge of human nature. A thrill of victory ran through her veins as she noted the effect of her Parthian shot. For Pierre Legros lifted his brown hands to his swarthy face and wept such a flood of tears as a British seaman could not have secreted, let alone shed, in a lifetime. She waited patiently till the paroxysm had passed, and then reaped her reward in a flow of excited verbiage which amounted to this—

He was one of the hands on a lugger which had brought a cargo of onions from France, and in the course of vending his wares about the country he had discovered his old sweetheart, Louise Aubin, in service at the Manor House. But her head had been turned by a succession of English admirers, and she would have nothing to do with him. Legros waxed somewhat incoherent about the personality of these swains, slurring over his first efforts to defeat his rivals in a jumble of phrases, from which, however sharp-witted Enid was able to form a distinct suspicion. Her father had hinted that the murder of Levison might be connected with the onion ship; she believed that she was shut up with the actual perpetrator of the crime.

Bringing his narrative down to date, in explanation of his concealment in the grounds of The Hut, Legros became more intelligible. Enid could hardly believe her ears when it transpired that Mr. Travers Nugent himself was the object of this half-demented creature's jealousy. She was convinced that he was the victim of some ridiculous error, since to associate the fastidious, middle-aged bachelor with a vulgar intrigue with a lady's maid was the height of absurdity. But there was no doubt that, however the misunderstanding had arisen, Legros was firmly convinced of its truth.

He had of late found that Louise was paying frequent clandestine visits to Nugent, and as a consequence he had spent much time in hanging about and spying on them. That very morning he had crept from the moor into the garden for the purpose, and he had been making his way through the shrubbery when he heard Nugent's voice coming towards him. He had taken refuge in the grotto, and had barely had time to conceal himself under the mats when Nugent had entered, accompanied by the man who had just now made them both prisoners by locking the door.

"They made plenty talk, ma'amselle, till my poor head ache," Legros continued with that note of self-pity which seemed his leading attribute. "And their talk was of 'the girl'—always the girl, and how she was to be deported—is that your word?—in a steamer that would come off the shore to-night. There was also talk of anozaire—a man, one Jermicide—who was to be deported and made what you call decoy for tempting her on to the steamer. The girl, cela va sans dire, is Louise Aubin, and Nugent, he run off with her. I not rightly know where Jermicide what you call come in, for I nevair heard of him. He must be one more of the lovers of Louise. She raise 'em like the mushrooms, here in your damp country."

Enid's active brain worked rapidly. The onion-seller had evidently got a bee in his bonnet which it was useless to try to disentangle. The salient fact stood out that Nugent had a project afoot for that night, in which all the principal actors in the Levison mystery, as enumerated by her father, were concerned, and of which her father would wish to be informed without delay. And here was she, his only possible informant, a prisoner without any prospect of release except at the hands of a cunning schemer who would have reason for preventing her from imparting the knowledge she had acquired. The action of "The Bootlace Man" in locking her in took a more sinister meaning by the light of what she had heard, and at the same time made her more than ever anxious to escape.

The suggestion that Violet Maynard's maid was the object of Nugent's machinations she dismissed with scorn, but that Leslie Chermside was to be "deported" in a steamer, either voluntarily or otherwise, was an item which ought to be under her father's consideration before it became an accomplished fact.

"I think that if I was out of this horrid place I could help you," she said. "Miss Maynard, the mistress of Louise, is a friend of mine. I would go to her and persuade her not to allow Louise any liberty to-night. Sailors are so clever, especially French sailors. I am sure that you will be able to hit upon some way of getting out."

The sun was low in the heavens, and inside the shrub-girt grotto it was scarcely possible to see the walls. Legros peered up at the little window, the top of which was just on a level with the eaves, where the slope of the roof began. Enid followed the direction of his glance, and pointed out that the aperture was not big enough for either of them to pass through. For answer Legros went and collected some of the patent fertilizer kegs, set them one upon the other under the window, and clambered up on to the topmost. By so doing he could easily reach with his hand the upper pane. It was already cracked, and, cautiously removing the broken glass, he thrust his arm through.

"From here I can make a hole in the roof big enough," he called down in a hoarse whisper. "It will take very long time to pick off the slates, they so firm fixed. But it the only way."

"Then, my dear good man, please begin at once," Enid urged him. "And don't make more noise than you can help in dislodging the slates, or we shall have that brute, or Mr. Nugent himself, round to stop us."

So she leaned against the mouldy wall and watched the laborious task with growing impatience, and in momentary dread lest the door should be flung open by the "bootlace man" or his employer. For though she was nearly certain that her companion of the grotto was a shedder of human blood her instinct told her that to her personally the forces controlled by Travers Nugent were far more dangerous.

The work of removing the roofing seemed interminable. The interior of the old stone building grew pitch-black before three of the slates had been displaced and gently tossed into the herbage. A distant clock in the town struck eight, nine, and ten and still Legros remained on his perch, toiling, with twisted body and arm crooked through the broken pane, in frantic endeavour to enlarge the opening.

At last the clock struck eleven, and before the half-hour the Frenchman slid nimbly to the floor.

"There, ma'amselle!" he panted after his exertions. "I t'ink there room now for you to pass through. For myself I shall have to make 'im one bit bigger. If you ready I give you what you call a 'and up."

Enid prepared to mount the kegs, grateful that she was wearing a short golfing skirt, but in no wise daunted at the prospect of crawling through the yawning gap in the roof or of the drop to the ground on the other side. But in the act of commencing her scramble on to the improvised stage she paused and clutched Pierre's arm.

"Hush!" she whispered. "I heard some one speaking. There are people close by—crossing the garden."

In a silence that could be felt they waited, and it was only when the voice which had disturbed her had passed beyond hearing that Enid wished that she had pursued quite other tactics and called out—called with the full vigour of her lungs.

For all too late she realized that the voice which had arrested her attempted escape was the voice of her friend, Violet Maynard. She tried to rectify her error by calling out now, but there was no response. Her shrill cry shot skywards through the aperture towards the blinking stars, but the thick stone walls stood between her and the ears the cry was meant for. Violet and Travers Nugent had passed through the door on to the moor on their way to the beach.