again a clock somewhere in the house chimed the hour. and again.

one o'clock.

two o'clock.

the embers in the fireplace had long since turned to black charred things. locke raised his head. two o'clock! he had not been conscious of it when the last little glow had died away. he had turned out the light when polly had gone—and had sat there staring at the dying fire. he had not put on another log. the fire was dead now—quite dead. he had been staring into a black fireplace—that was as black as the room itself.

two o'clock!

he stood up, and, going to the windows, flung back the portières. it was still blowing hard; but the moon was beginning to show through the scudding clouds. he brushed his hand heavily across his eyes. it was very still in the house; but the stillness itself seemed a disquiet, untranquil, chaotic thing. polly! yes, polly had filled his thoughts during those two hours—polly, and captain francis newcombe. but he had not forgotten withal the bizarre appointment he was to keep with mr. marlin in the aquarium—at a quarter past two. one would not be likely to forget so extraordinary a thing in any case, no matter what might meanwhile have intervened—even if mr. marlin had not been so grotesquely persistent in his reminders. a dozen times that day the old man had plucked significantly at his, locke's, coat sleeve, or had signalled mysteriously with his finger to his lips; and twice, with a childish titter, the old man had come upon him unexpectedly and had said exactly the same thing on each occasion.

"tee-hee, tee-hee!" the old man had tittered. "it is all right for to-night, my boy—you will see—you will see. and they thought i was a fool. do not say a word. keep quiet—keep quiet—you will see."

what would he see? what would he learn? much—or little? would it be only the babble of a sick brain? queer, strange, almost impossible conditions in this house! where would they climax—and how? whose hand held the trumps?

his eyes fixed suddenly on a spot across the lawn. something seemed to have moved there. fancy, perhaps; or a shadow cast by the swaying branches. the moon was just coming out from under the edge of a cloud—another moment and he would be able to tell if anything were there. yes! a woman emerging from the path that led to the shore. the figure began to cross the lawn, approaching the house.

and then locke's eyes narrowed suddenly in astonishment. it wasn't a woman at all; it was a man wearing a long gown, a dressing gown. it was mr. marlin. and the man kept cocking his head from side to side; and he appeared to be carrying something under the dressing gown—at least his arm was crooked up as though he held a bundle there.

locke smiled now a little grimly, as the old man finally disappeared around the corner of the house. it was almost a quarter past two. he would find mr. marlin in the aquarium.

he drew the portières together again, and, leaving the room, went out into the reception hall beyond. there was no light showing anywhere and he was obliged to feel his way along. the aquarium was in, or, rather, composed in itself, a little wing built at the rear of the house, but connected therewith by a short, covered passageway. he knew the way quite well—he had been there with polly on that first day.

that first day! that was only yesterday ... it was incredible, impossible.... his mind was running riot as he groped his way to the rear of the main staircase and into the wide passage that ran parallel with the length of the house. but then the whole place was incredible! the house itself was like a great hotel with its corridors and its endless number of rooms! this was mr. marlin's room here at his right, and—

he stood still. a door on his left had opened. it shut again instantly—and then he could hear it being cautiously reopened a little way.

"don't you move!" said a voice in a fierce whisper. "don't you move! i can see you! if you move i will shoot you!"

locke found his muscles, that had suddenly grown tense and strained, as suddenly relaxed. he could see nothing—the door wasn't wide enough open—but it was the old madman's voice. strange, though! how had the man got there? that wasn't mr. marlin's room—mr. marlin's room was on the opposite side of the hall. yes, of course, there must be an entrance into the house there of some sort.

"it's locke," he announced quietly. "that's you, mr. marlin, isn't it?"

"hah!" ejaculated the other. "you, my boy, eh? well, that's quite different. of course, it's you. you know the value of being prompt. excellent! excellent! be very quiet—but hurry! follow me. we have only a little time."

locke could just make out the old man's form now as the other came through the door—and then in the darkness it was lost again. but the patter of footsteps ahead of him, hurrying along, served as a guide. he followed the other to the end of the hall, turned into the covered passageway, and was halted again by the old man, this time at the door of the aquarium.

"tee-hee!" tittered the maniac. "they think they are dealing with a fool. wait! wait, young man, i will see that the window shades are all down before we turn on the light—though there will be no one here to-night except ourselves—tee-hee!—they will be somewhere else!"

the old man opened the door and disappeared. and now locke, as he waited, and though he listened, could not hear the other moving around inside—what sound the old man made was drowned by the noise of running water through the pipes that fed the tanks, and, added to this, the low, constant drip and trickle that pervaded the place.

presently the lights went on.

"here!" cried the old man. "come over here!"

locke blinked a little in the light as he stepped forward. it reflected bewilderingly from the glass faces of the tanks that were everywhere about. he joined the old man in the centre of the aquarium. here there was an open space from which the tanks radiated off much after the manner of the spokes of a wheel, and this space was utilised as a sort of luxurious observation point, so to speak, for a heavy oriental rug was on the tiled floor, and ranged around a table were a number of big easy chairs.

from under his dressing gown now the old man took a package that was wrapped in oiled silk, and laid it on the table.

"money!" he cried out abruptly. "hah! we know its power, young man, you and i!" he began to fumble with the cord that was tied around the package; and then suddenly commenced to titter again. "did i not tell you i was being followed, always being followed? well, last night they followed a wrong scent. tee-hee! tee-hee! i told you you would see who was the fool! they are there to-night—digging—digging—digging. tee-hee! tee-hee! they will dig the place all up before they are sure it is not there."

money! that package! locke's lips tightened a little. was this, as he had more than half expected, what he was to "see"—the half-million dollars at last that polly had seen? and what did the man mean by "wrong scent"? and "digging"?

"yes, of course, mr. marlin," said locke quietly. "of course, they will! but who is it that is following you?"

the old man dropped the package from his hands and leaned across the table, his eyes suddenly ablaze.

"if i knew, i would kill them!" he whispered. "it is everybody—everybody!"

"perhaps you are mistaken." locke spoke in a soothing tone. "did you see anybody following you last night?"

"it is not necessary to see"—the old madman's whisper had become suddenly confidential—"i know. they were there—they are always there—watching—eyes are always watching." he broke into his insane titter once more. "tee-hee, yes, yes; and we are being watched by thousands of eyes to-night—look at them—look at them—the pretty things—see them swimming all around you—but they look and they say nothing—and they do not follow me." his voice was rising shrilly; he began to gesticulate with his hands, pointing with darting little motions at one tank after another. "do you hear? you need not be afraid because they watch. they will not follow us."

locke sat down leisurely in a chair facing the other across the table. he was rather curious about this mysterious digging of last night, a little more than curious—but, also, it was necessary to calm the old maniac's growing excitement.

"i am quite sure of that, mr. marlin," he agreed heartily. "we should be perfectly safe here, especially as you say that you have succeeded in making whoever was following you watch somewhere else. that was very clever of you, mr. marlin."

the old man put his finger to his lips.

"i'll tell you where it was, young man," he said. "the old hut in the woods behind the house. they think it's there. they think that's where i hide the money. and they'll keep on looking there. it will take them a long while. they will be looking there to-night—and perhaps to-morrow night, too. and then they will begin to follow me again. but it will be too late—too late for many, many days, because the time-lock will be set—ha, ha—god supplies the time-lock, young man—you do not understand that—but can you imagine any one opening a time-lock that god has made?"

locke took refuge in a cigarette. apart from some mare's nest in an old hut, it was quite hopeless! the old maniac's condition was growing steadily worse. there was a marked change in even the last twenty-four hours. it did not require any professional eye to discern that.

"i think," suggested locke conversationally, "that you were going to show me something in that package, mr. marlin."

"yes," said the old madman instantly, and as though quite oblivious of any digression. "that is why you are here. listen! you will tell your father about it. i do not ask others to do what i do not do myself. your father must do the same. he must get all the great capitalists of america to do likewise—it is the only thing that will save the country from ruin and disaster. look!" the old man ripped off the cord and wrapper, and there tumbled out upon the table, each held together with two or three elastic bands, a half dozen or more small bundles of bank notes. "see! see! do you see, young man?"

locke with difficulty maintained an impassive countenance. he had expected something of the sort, but it seemed somehow incredible that a sum so great as polly had named should be represented by those few little bundles scattered there on the table in front of him. he picked one of them up and riffled the notes through his fingers. it contained perhaps a hundred bills, each one of the denomination of a thousand dollars—one hundred thousand dollars. he laid the bundle back on the table. others were of like denomination; others again of five hundred. the full amount was undoubtedly there.

"do you know how much is there?" demanded the old madman sharply.

locke regarded the money thoughtfully. to name the exact amount offhand might aggravate the old maniac's already suspicious frame of mind.

"i can see that there is a very large sum," he answered cautiously.

"a large sum!" echoed the madman aggressively. "and what do you call a large sum, young man?"

"well, at a guess," said locke quietly, "and basing it on that package i have just examined, i should say in the neighbourhood of half a million dollars."

the old maniac thrust his head forward across the table, stared for an instant, and then suddenly burst into a peal of wild, ironical laughter.

"half a million!" he rocked upon his feet, his peals of laughter punctuating his words. "bah! there are five millions, ten millions, fifty millions there!" he shook his finger under locke's nose. "do you hear what i say, young man?"

the blue eyes had become alight with a mad blaze; hectic spots began to burn in the old madman's cheeks. locke nodded his head in a slow, deliberate manner—as the most effective thing he could think of to do by way of calming the other. the whole place, the surroundings, the grotesque shapes swimming around in the tanks everywhere he looked, the eyes of the queer sea creatures that all seemed to be fascinated by that fortune which lay upon the table, the constant drip and trickle of water, the crazed old man who rocked upon his feet and laughed, were eerily unreal. that sea-horse in the tank that faced him from just beyond the other side of the table, for instance, seemed to be a most bizarre and unnatural creature both in shape and actions even for one of his own species! half-past two in the morning, in an aquarium with a madman and a half-million dollars! again, by way of appeasing the other, he nodded his head.

"listen!" cried the old maniac fiercely. "you must help me. men are blind, blind, blind! europe is crumbling, nations are bankrupt—chaos—chaos—chaos is everywhere. everything else is decreasing in value; only the american dollar climbs up and up and up. sell, sell, sell while there is time! commercial houses are tottering, dividends are not being paid, the employment of labour becomes less and less—the end is near. and fools cling to their business enterprises; and their capital shrinks and is swallowed up and lost. lost!" the man was working himself into a frenzy. his voice rose in a shriek. "lost! do you not see? do you not understand? money alone has any value. and the less money there is left in the world, and the more that is lost, the greater will be the value of what remains. it will multiply itself by the thousandfold. look! look what is on the table here! it will become a wealth beyond counting in any case, and if no one will believe me then the more it will be worth because there will be the less money to compete against it. millions! millions! hundreds of millions! but i am not selfish. i do not wish to see the ruin of the world. and you—you! you will now be responsible. they will not listen to me because they say i am mad—i, who alone have the vision to see, and the courage to act. but your father will listen to you and he will believe you, and the great financiers of america will follow your father, and—"

subconsciously locke was aware that the old maniac was still talking, the crazed words rising in shrieks of passionate intensity—but he was no longer paying any attention to the other. he was staring again at the glass tank, behind and a little to one side of the old madman, that contained the sea-horse. the creature was most strange! it was only a small and diminutive thing, but, unless he were the victim of an hallucination, it had taken on an extraordinary appearance. it seemed to possess human eyes; to assume almost the shape of a face—only there was a shadow across it. the water rippled a little. the sea-horse moved to the opposite corner of the tank—but the eyes remained in exactly the same original spot.

locke leaned nonchalantly back in his chair, though his lips were compressed now into a thin, grim line. they were human eyes, and the shadow across the face was a mask. where did it come from? he began trying to figure out the angle of reflection. the face of each glass tank, of course, with the deeper-hued water behind it, was nothing more or less than a reflecting mirror. what was that dark straight line above the eyes? to begin with, the reflection must come from somewhere behind him, and well to one side of him. taking into consideration the position in which mr. marlin stood, it must be the left-hand side. the tanks, then, that would seem to answer that requirement became instantly limited in number—it must be either the first or second tank of those that formed the left-hand side of the alleyway nearest to where he sat, and that, like the spoke of the wheel, led obliquely to the wall. he could not see the wall, but— yes, he had it now. there was a window there. that dark line above the eyes was the window shade—raised six inches or so from the sill. it could easily have been accomplished—even if the old madman had carefully drawn every shade and shut every window in the place, as presumably he had. the drip and trickle, the running water, would have deadened any little sound made in forcing the window, and after that to reach in and manipulate the shade would have been but child's play.

locke's eyes shifted now to the old madman. what was to be done? the other, still rocking and swaying upon his feet, still flinging his arms about in mad gestures, his facial muscles twitching violently as he shrieked out his words, was already verging on a state of acute hysteria. even to hint at the possibility that they were being watched would not only have a probably very dangerous effect upon the maniac, but would in itself defeat any chance of turning the tables on that watcher outside the window! whose eyes were those, whose face was that behind the mask? intuitively he felt he knew—the trail went back, broad and well defined, to london. newcombe! captain francis newcombe! who else could it be? his jaws clamped hard together now. how turn intuition into a practical, visible certainty—by stripping that mask from the other's face?

the eyes were still there in the tank.

his mind was working keenly, swiftly now. suppose he made some excuse to leave the aquarium and stole around outside to that window? no; that would not do. in the first place, he probably could not get away from the old madman; and, if he could, he dared not, for the length of time it would take him to accomplish any such purpose, leave the other alone with that money on the table and subject to attack from an open window only a few feet away. there was only one thing to do. the man outside the window there, unaware that his presence was known, would naturally not consider that he, locke, was a factor to be reckoned with when, say, the old madman left the aquarium here to return the money to its hiding place, wherever that might be; and therefore, if he, locke, could manage to keep ward over mr. marlin without being seen himself, the man out there would almost certainly rise to the bait and bring about his own downfall. the money was in evidence for the first time; its whereabouts known—and the man in the mask would be illogical indeed if he allowed it to be restored to the security of a secret hiding place without making an attempt to get it when an opportunity such as this apparently presented itself. but against this was a certain risk to which the old man would be subjected; if not a physical risk, then a mental one—which latter, to one in mr. marlin's condition, would probably be the more dangerous of the two. and then there was the chance, too, that if luck turned an ugly trick the money itself might be in jeopardy. the old maniac's unconscious co-operation must be secured. the hiding place was somewhere outside the house. that was obvious, both from mr. marlin's nocturnal habits, and from the even more significant fact that the old madman, in coming to this appointment here to-night, had brought the money with him from somewhere outdoors. also it seemed to be no secret that mr. marlin roamed abroad at night. polly had spoken of it without reserve. it was therefore but fair to presume that one as interested as was the man outside the window, and particularly if it were newcombe, was in possession of this knowledge, and being in possession of it was equally capable of putting two and two together, and would expect the old maniac to go out again to-night—with the money. if then, without unduly alarming him, mr. marlin could be persuaded to remain in the house with his money to-night, it would not only be the safest thing the old madman could do, but would afford him, locke, if he were right in his supposition, an excellent chance to trap the man in the mask while the latter waited for his prey to come out.

locke, leaning forward now, crossed his arms on the table, and nodded his head earnestly at the old maniac. one corner of the table at least was distinctly visible from where the window would be along that little alleyway between the rows of tanks, but he was careful not to glance in that direction. the reflection of the masked face still showed in the same place. what was the old madman saying? well, it didn't matter, did it? he interrupted the other now.

"you are right, mr. marlin," he said gravely. "i agree with everything you have said. it is a most serious situation. i had no idea that there existed any such vital and immediate necessity of realising cash for every description of asset that we can lay our hands upon. and i had no idea of the immense potential value that this money here on the table, for instance, possesses. as you say, when the crash comes it will be worth untold millions—a fabulous amount."

"yes, yes!" agreed the old man excitedly. he began to pat and fondle the bundles of bank notes. "millions! millions! hundreds of millions!"

"the amount is so vast," said locke, still earnestly, "that i cannot help thinking about what you said in reference to being followed out there in the woods last night. i don't think you should risk any chance of being followed to-night when you have all this great wealth with you, even though you are quite sure you have put whoever it may be off the scent, and that he, or they, will be busy somewhere else. i don't think, if i were you, i would go out of the house again to-night."

the old madman straightened up, and for a moment stared at locke; and as he stared the red spots began to overspread his cheeks, and the pupils of the blue eyes seemed to enlarge and darken. and then with a sudden sweep of his arms he gathered the bundles of bank notes together, wrapped them up frantically in the oiled-silk covering, and thrust the package under his dressing gown.

"hah!" his voice rose in a wild and savage scream. "you think i should stay in the house, do you? hah! i see! i see! that is what you want me to do, is it? you want to trick me! you are one of them—one of them—one of them! you could never find the money where i hide it! you could never open god's time-lock! so you want me to keep it in the house to-night where you can get it! and you think that i am a madman and cannot see what you are after! you are one of them—one of them that follows—follows everywhere—and watches—and watches!"

he burst into a wild peal of laughter—another and another. he clutched fiercely at the package under his dressing gown. his face was distorted. his free hand pounded the table; saliva showed at the corners of his lips.

"for god's sake, mr. marlin," cried locke, "listen—"

"one of them! one of them!" screamed the old man—and, turning suddenly, dashed for the door.

locke's chair overturned with a crash as he sprang to his feet, and, darting around the table, started to follow—but the old maniac by now was already at the door. he saw the other's hand snatch at the electric-light switch. the aquarium was in sudden darkness. he heard the door slam. he groped his way to it, and wrenched at it.

the old madman had locked it on the outside.