an hour to daybreak! passion, unchecked and unrestrained, was stamped on captain francis newcombe's face as he dressed now with savage, ferocious haste. he swore and snarled, making low venomous sounds in the fury that possessed him. there was no longer room for the fear that last night, here in his rooms, had gnawed at his soul itself—the fear of the unknown; there was no longer room for fear in any sense, whether born of the intangible, or whether it knew its source in man, or god, or devil—there was only murder, that alone, in his heart.

the blows were coming nearer and nearer home. too near! and his efforts to strike one in return had resulted in little to boast about so far! disaster, ruin, that dangling gibbet chain, were inevitable if this went on. he had been too cautious perhaps! well, that was ended now! he swore again—bitter, sacrilegious in his rage. the luck had been running against him. even an old fool had tricked him—even a maniac, a cracked-brained idiot, and one almost in his dotage besides, had tricked him! last night after he had read that infernal message at the hut he had made no effort to uncover the madman's horde—he had lain there waiting. hours of waiting, patient waiting—listening—his revolver in his hand—the one chance that the unknown might not have gone away, might have lingered, hidden in the foliage, to gloat—and die. he had waited in vain. to-night he had gone back to the hut only to find after hours of search that the old madman's money, wherever else it might be, was not there. and then he had returned here—and again the unknown had struck swiftly, viciously, cunningly.

when, where, how would the next blow fall?—unless he could now strike the quicker, and strike surely! how much farther was it to the abyss of exposure? to-night he had stood perilously close to its edge, hadn't he? if he had not been able to pull the wool over polly's eyes with the specious explanation that it was old marlin who had telephoned, he would—

he stood suddenly motionless, tense, with his coat half on, his working lips drawn for the moment tight together. had it been, after all, merely a specious explanation? was he so sure that it wasn't old marlin, after all, who had telephoned? the old madman was cunning; and, granting that fact as a premise, his act last night in pretending to go to his money in the hut must have been prompted by suspicion of some sort. the money had never been in that hut. the bit of flooring that was loose was flush with the ground beneath, and the ground had never been disturbed—and this was true of everywhere else in the hut. the old maniac, then, was suspicious that he was being followed by somebody, and had set a false trail. of whom would he be suspicious? the question answered itself. the newcomers on the island, of course. and, being suspicious of them, he would want to drive them away. to frighten polly into the belief that her mother was dead might very easily appeal to an insane brain, and even to one that wasn't, as a very clever and effective means of accomplishing this end surreptitiously. polly might very logically be expected in her grief to wish to bring her visit here to an end, even if she did not, indeed, insist on returning to england at once—and the result would be that all who had come here, locke, runnells and himself, would naturally leave with her. why not? the madman was certainly cunning enough; he could have telephoned—and the motive was there.

no! with an angry, self-contemptuous snarl, captain francis newcombe jerked on his coat. was he trying to qualify for an insane asylum himself? the old maniac could have done this to-night, otherwise the explanation made to polly would have been merely an absurdity; but old marlin had not been on the liner and could not have fired that shot through the cabin window—nor could the old man have known, as instanced by that voice in the woods, that he, newcombe, was shadow varne—or known anything of the murder of sir harris greaves. the man who had telephoned to-night—making the fourth mysterious blow that had been struck—was the man who had showed his hand on those three former occasions. this was so blatantly obvious that to have allowed his brain to shoot off at a tangent so idiotic but increased his anger now.

he sneered at himself as he finished dressing. there was only one man on the island who could be made to fit into each and every one of the four niches. runnells! runnells had been on board ship, even though at the time runnells had apparently been asleep; runnells was in a position to know, and to know what now appeared to be certainly too much, about shadow varne; and runnells, though the man could prove nothing, was, more than any one else, in a position to entertain suspicions in reference to the murder of the baronet who meddled so gratuitously with the affairs of others.

captain francis newcombe slipped a flashlight and a revolver into his pocket, and made for the door of his room. quite so! all this was nothing new—no new angle—he had mulled this over a hundred times before. but up to now he had held his hand—and for two very good reasons. in the first place, he had not been able to bring himself to believe that it was runnells, for he could not see where runnells would profit by any such game; and, secondly, as he had already argued with himself, should it not prove to be runnells, he almost inevitably disclosed his own hand and his real purpose in coming here to manwa island, and it would in that case make a partner of runnells—and partners shared in the profits! but the time for hesitation on any such score as that was gone now; not only because the ice he was treading on, already thin, had nearly broken through to-night, and the promise of imminent and final disaster was forcing his hand, but because, in respect of runnells, the absence of apparent motive—runnells would be made to explain that!—counted for nothing now in view of the fact that he, newcombe, had more to go on to-night than he had had before. not only was runnells one who fitted into the role of the "unknown" on each of the four occasions, but runnells, as though to clear the matter of all doubt, knew what surely no one else on the island could possibly know—that mrs. wickes actually was dead. he, newcombe, had himself to blame for that, and it appeared now that he had trusted runnells too far; but somebody had had to bury the old hag. not captain francis newcombe! to have left her in the status of a pauper for the authorities, or the mission boards, or any of that ilk to have taken care of, and in view of the fact that it must have been known amongst her neighbours that she had for a long time received money from somewhere, talk, comment, investigation, official this and official that would have been invited. it might have amounted to nothing—but if a rock that is held in one's hand is not thrown into the calm waters of a pool the placid surface is not disturbed! he had delegated runnells to interview the undertaker and arrange for the quiet and unostentatious disposal of mrs. wickes' mortal remains. runnells, for the time being, did very well as a nephew of the deceased, who, though in neither close nor loving touch with his somewhat questionable relation, at least recognised the family tie to the extent of paying for her very modest and unpretentious obsequies.

captain francis newcombe crept quietly along the hall now. runnells' room, thanks to the hospitable thoughtfulness of miss marlin, in order that the "man" might be nearer at hand and therefore the better able to serve his "master," was not in the servants' quarters, but was at the extreme end of the hall here just at the head of the stairs. captain francis newcombe's hand felt along the wall to guide him in the darkness. he had no desire to stumble over anything and arouse anybody; locke, or dora marlin, for instance—and he had not forgotten that polly was probably lying wide awake. the only one to be aroused was runnells—and that very quietly. runnells was a professional criminal, not a particularly clever one, but possessed, where a question of self-preservation was concerned, of a certain low cunning born of his hazardous career, a cunning that was not to be ignored. cornered here in his room, for instance, runnells, though quite well aware that he, captain francis newcombe, would have no more hesitation about putting an end to him than an end to an obnoxious fly, would be equally well aware that here in the house he was possessed of a defence that rendered him invulnerable because no threat could be put into execution in silence, and that a cry, a shout, and, if necessary, to those who came to his succour, a confession of his own past misdeeds in order to prove his alliance with, and implicate his "master" in criminal intrigue, would protect him—for the moment—utterly.

but he, captain francis newcombe, had no intention of making any such unpardonable misplay as that! runnells would never look down the barrel of a revolver with a confidence born of the fact that the trigger dared not be pulled; runnells would never feel a grip upon his throat and still be able to defy the clutching fingers because he knew they feared the cry, the gasp, the noise of strangulation. it would not be in runnells' room that the man would lay bare his soul through fear to-night! runnells would be played as a fish is played!

captain francis newcombe was halfway along the hall now. his mind, despite the fury that from smouldering rage had broken into flaming heat, was logical, measured, precise. that telephone message could have come from nowhere else but from the boathouse. that was self-evident. if runnells, then, was at the bottom of this, the question now was whether runnells had got back to his room yet or not? and, if he were back, how long he had been back?—the man must be allowed to undress and get into bed. to discover runnells fully dressed at this hour was to force the issue then and there in runnells' room; for runnells, caught like that, while he might be voluble with explanations, would of necessity at the same time be thrown instantly upon his guard, and would not be fool enough to be enticed into any trap, no matter how apparently genuine the pretence of accepting his explanations might be made to appear.

captain francis newcombe was at the door now listening. runnells would have had time by now to have got to bed; certainly there was no sound from within, and— he drew back from the door suddenly, but as silently as a shadow. there was no sound from within, but some one was creeping, though with every attempt at silence, up the staircase. captain francis newcombe retreated still a little farther back along the hall, and, with body hugged now close against the wall, waited in the darkness. he could see nothing—not even across the hall; and, therefore, he was quite secure from being observed himself, but his hand, in his pocket now, was closed over the butt of his revolver.

the sounds were very faint, but they were equally unmistakable—now the muffled, protesting creak of a stair tread; now that sound, like no other sound so much as the padded footfall of an animal, as weight was cautiously placed on the carpeted stairs. the footsteps came nearer and nearer to the upper landing, slow, laborious in their caution and stealth. and then another sound—equally faint and equally unmistakable—the opening and closing of the door at the head of the stairs.

captain francis newcombe relaxed. his lips twisted into a smile of malignant satisfaction.

runnells!

so it was runnells who had indulged in that little telephone conversation; runnells, the pitiful, foolhardy moth—and the flame! runnells, instead of being already in bed, was just getting back. so much the better—it would tax runnells' ingenuity a little beyond its limitations to explain this unseemly hour! it made it perhaps just a little easier to handle and break the man.

captain francis newcombe moved silently back again to the door of runnells' room, and again listened at the panels. the sound of movement from within was distinctly audible. runnells was preparing to go to bed.

the minutes passed—five—ten of them. it was quiet inside the room now. and then captain francis newcombe knocked softly with his knuckles on the door—two raps in quick succession, then a single one followed by two more.

there was a sound almost on the instant as of the sudden creaking of the bed, and then the hurry of feet across the floor to the door. then silence again. captain francis newcombe smiled thinly to himself. runnells was caution itself. he repeated the knocks precisely as before.

the door opened. runnells showed as a white, vague figure in his night clothes.

"what's up?" whispered runnells anxiously.

"i'm afraid we've been spotted," said captain francis newcombe tersely.

"spotted!" runnells echoed the word with a gulp. "who by?"

"some swine from the yard, i suppose," replied captain francis newcombe as tersely as before. "do you remember detective-sergeant mullins?"

"him?" gasped runnells. "my gawd, he ain't followed us here, has he? strike me pink! my gawd! i said all along it was damned queer him showing up at the rooms that night. are you sure?"

"not yet—and i never will be if you stand there gawking," said captain francis newcombe sharply. "go and get your clothes on—and hurry up about it! it'll soon be daylight. every minute counts. meet me down on the verandah."

he did not wait for runnells' reply. it was not necessary. runnells had swallowed bait, hook and line. captain francis newcombe indulged in a low, savage chuckle, as, descending the stairs, he unlocked the front door and stepped quietly out on the verandah. he had not lunged in the dark, nor was it chance that had prompted him to endow his bogey with the personality of detective-sergeant mullins—he had not forgotten runnells' white face on the occasion when the man from scotland yard had sent in his card!

and now as he waited on the verandah, the low, savage chuckle came again. the boathouse would serve admirably—since runnells seemed to have a penchant for it! it was far enough away to obviate the possibility of any sound carrying to the house; and, inside, it possessed light. he wanted light when he handled runnells! quite apart from the fact that darkness in itself afforded too many chances for a lucky escape, he could not read runnells in the darkness. also, affording him a malicious delight, there was exquisite irony in the thought that the setting for what was to come should be the one that runnells had himself chosen to-night—for quite another purpose than that it should be the scene of his own undoing!

the front door opened and runnells emerged.

"what's the game?" runnells asked hoarsely. "d'ye know where he is?"

it was quite unnecessary to be anything but frank with runnells as to their destination. runnells, safe in the belief that he had been mistaken for one detective-sergeant mullins and that his "master" was wide of the mark and astray, would also enjoy the irony to be found in a trip to the boathouse. it would be a pity to deprive runnells of anything like that! captain francis newcombe nodded curtly, as, motioning the other to follow, he led the way across the lawn.

"yes; i think so," he said. "i've reason to believe he's been using the boathouse to hide and live in."

"strike me pink!" mumbled runnells. "that's what i always said to myself after that night: i says, 'look out for that bird'—and i was bloody well right."

"i fancy you were," agreed captain francis newcombe coolly, "though i didn't think so at the time. but hurry up! there's no time to lose if we want to trap him."

they had entered the wooded path leading to the shore, and, curiously enough, runnells was now in front—and in the darkness, as it swung at his side, captain francis newcombe's hand held a revolver.

"how'd he get here?" runnells jerked back over his shoulder. "how'd you twig it? and when did he come?"

"about the same time we did, i imagine," replied captain francis newcombe shortly. "don't talk so loud—or any more at all, for that matter. the wind has died down a bit, and we might be heard. make straight for one of those little bridges at the boathouse—the one on this side—the nearer one. understand? and look out for yourself—the man's no fool, i'll say that for him."

"right!" said runnells in a muffled voice, as they came out of the woods and the boathouse loomed up, shadowy and indistinct, some fifty yards away.

there was laughter in captain francis newcombe's soul now, a mirth parented out of savagery and vindictiveness, a laugh at the blind fool treading so warily and cautiously and silently across the sandy beach here in order that he should not be denied the shambles! the laugh seemed to demand physical, audible expression. he choked it back. in a moment or so more he could laugh to his heart's content. the boathouse was only a few yards away now. he rubbed close against runnells' side, as though to preserve touch with the other in the darkness. runnells' revolver was in the right-hand coat pocket, and—

both men had halted simultaneously. close to the boathouse now and in its lee, the sound of the breaking waves was somewhat deadened, but from under the overhang of the verandah there had come another sound, as though a vicious slapping were being given the comparatively smooth water under the boathouse, and then a sudden floundering and splashing, and then the slapping again.

runnells' hand went to his side pocket—but as it came out again with his revolver captain francis newcombe's hand closed upon it like a vise, and with a quick twist and wrench secured the weapon.

"what—what did you do that for?" runnells stammered in a low, startled way. "didn't you hear that in under the boathouse? there's some one there. maybe it's him."

captain francis newcombe laughed now—aloud.

"so you think there's some one in under there, do you, runnells?" he drawled.

"yes," said runnells, and drew away a little. "you heard it just the same as i did, but—but i don't understand what you—"

"you will in a minute!" captain francis newcombe's voice was still a drawl. "but meanwhile we'll see whether you're right or not. you don't mind going first, do you, runnells?" his revolver muzzle was suddenly pressed against the small of runnells' back. "i've known you to be a bit tricky at times. go on!"

something like a whimper came from runnells. he stood irresolute.

"go on! in under there! we'll see this 'some one' of yours first of all!" captain francis newcombe's voice snapped now. "move!"

a push from the revolver muzzle sent runnells forward.

"what—what are you doing this to me for?" the man burst out in a shaken voice again.

captain francis newcombe made no answer. he too had heard the sounds in under here, but if runnells were up to some more of his games it would avail runnells very little now. runnells' body, if there were by any chance some one ahead here in the darkness, made a most excellent and effective shield. it was inky black in here, and now underfoot, as they went forward, in place of the pure sand there were rocks and a slightly muddy bottom.

his left hand deposited the surplus revolver in his pocket, and in exchange drew out his flashlight. he thrust the flashlight out beyond runnells' side in front of them both, and switched it on.

a cry broke on the instant from runnells' lips—a cry of terror.

"look! look!" runnells cried. "let me go! let me get out of here! this is a horrible, slimy, ghastly hole! let me go—let me go! it's—it's a dead man!"

captain francis newcombe's jaws had clamped. into the focus of the round white ray had come the big concrete pier that supported the building in the centre, slime-draped, green and oozy now with the tide still low; and, nearer in again, a black ribbon of water, strangely like silk in its rippling under the light, for the sea wall way out beyond had lulled it here into the quiet almost of a pond, lapped at the shore, lapped and lapped, as though striving with hideous patience to creep yet another inch onward, and yet another, and always another, that it might reach a huddled thing that lay still several yards away.

a huddled thing!

captain francis newcombe pushed runnells ruthlessly forward until they both stood over it. and now the flashlight's ray played upon it—upon a twisted, crumpled form, a dead thing, a man whose clothes in places were in ribbons as though the very body had been mangled, a man in a white shirt sleeve where the sleeve of the coat had been torn away at the armpit, a man around whose neck and across whose face were long, horribly regular lines of round, lurid marks, near purple now against the bloodless skin.

and runnells with a scream shrank back and covered his face with his hands.

"my gawd!" he screamed out in terror. "it's paul!" he screamed. "it's paul cremarre!"