The door closed behind Whitie Jack, the man’s footsteps echoed back as he climbed to the street, echoed faintly again from the pavement, and then died away.

Billy Kane got up from the bed, went to the door, locked it, and then walked down the length of the room—and standing in front of the mirror stared into the glass in a grimly impersonal way. It was himself—Billy Kane. His face was in no whit changed, except perhaps that there was a slight pallor there due to loss of blood, and that the lines were sharper and harder, as though he were, as indeed he was, under a tense and heavy strain; but, with his collarless shirt, his trousers covered with mud and dirt, his whole appearance had taken on an aspect that was at once sinister and forbidding.

He laughed shortly, and turning abruptly from the mirror, crossed the room again, and pushed aside the cretonne hanging. There were some clothes on the wall pegs here. He gathered them up, and took them nearer to the light for an inspection. They were old, somewhat greasy, and wholly disreputable. He laughed shortly again, as he changed into them. As the Rat, he might venture out, though he would do well to take care not to be recognized, since Whitie Jack would have spread the report that he was wounded and in bed; but he could at least go out without inviting instant pursuit as the “murderer” of David Ellsworth. He was safe now for the moment, safe until morning anyhow—and he could even use those hours, if he would, in an attempt to put as many miles as possible between himself and New York! His hands clenched, and into the pallor of his face the red came burning hot. But he wasn’t going to do that! That “staggering possibility” was clear before his mind’s eye now. He wasn’t going to do that; he was going, instead—to play the Rat—to play the cards that fate, if one believed in fate, had thrust into his hands—to take the chance, the one chance, if the Rat did not come back too soon, of clearing his own name, and of bringing to justice the hell-hounds, who had struck down that gentle gray-haired man who had been his friend. His hands clenched harder, until, as they had done once before that night, the nails bit into the palms. He, Billy Kane—the murderer of his father’s friend, the murderer of the man who had trusted him and loved him! It was getting him now with all its brutal and remorseless force! Broadcast over the country, by morning his name would have become the synonym of all that was vile and hideous, and Billy Kane would be known as one of the most revolting characters in the annals of crime—a foul and filthy thing who typified the dregs and lees of human degradation—a thing from whom the friends of old would turn in horror and in shame, and——

Slowly his hands unclenched. The surge of fury that had been almost ungovernable passed, and he knew again that cold, unnatural, deadly calm. If he lived, the guilty man, or men, would pay! If he were taking a chance now, a desperate chance, he was taking a chance that no man could do otherwise than take. It was the chance to live—for one might better otherwise be dead! A chance! He had picked up Whitie Jack’s revolver, and was twisting it in his fingers, and now he thrust it suddenly into his pocket. A chance! He was taking no chance, indeed, save with the stake that was already flung upon the table—his life. It was the one way! As the Rat, doubtless well known to the authorities, he could move under the very noses of the police at will without suspicion arising that he was Billy Kane; and as the Rat, if Whitie Jack was to be relied upon as a criterion, he would have the run of the underworld, and in the underworld were many secrets, and amongst those secrets was perhaps the one he sought—the clue to Jackson’s associates in the murder of David Ellsworth. He was not blinded to the difficulties of this picking up of the thread of another man’s life; nor blinded to what was perhaps the greatest difficulty of all, the necessity of being able to recognize those with whom he should be acquainted, but even that was not insurmountable. He could see a way, he believed, to accomplish even that.

But all this was for to-morrow—and the to-morrows after that! To-night he was going out again—to Marco’s. That was why he had changed his clothes just now. A graver thing, the thought of merging his identity with the Rat’s, had impinged, obtruded itself, as it were, upon his mind. But he had not forgotten Marco’s.

He picked up his discarded vest, transferred the package of banknotes and his watch to the pockets of the one he now wore, and as he did so, he looked at the time. Laverto had said a quarter to eleven. It was almost that now. Billy Kane’s eyes strayed over the table, and fell upon the black mask. The mask, too, went into his pocket. It might prove a most valuable discovery, that mask—under certain circumstances even the Rat’s identity was not lightly to be disclosed.

He collected the muddy garments he had taken off, and tucked them under the mattress on the bed. It was not likely that anyone would come here, much less attempt to enter, in his absence; but he was fully aware that now, and from now on, his life depended upon his caution in every detail. He extinguished the light, put on his hat, walked to the door, unlocked it—and stood for a moment hesitant. Was he a fool to take this added risk, when already his own back was against the wall, when already he was in desperate case himself? He shook his head in a sort of exasperated remonstrance with himself for even his momentary hesitation, then opening the door, he locked it behind him, and crept cautiously up the stairs to the street.

Whitie Jack had been only a tool used for the stage-setting of some deviltry that was to follow—at a quarter of eleven. That was obvious. He, Billy Kane, had intended that the police should be informed and should deal with Laverto, and that he in person should give evidence against Laverto; but he could no longer inform the police, no longer give evidence. He was wanted now himself for murder, and so upon him fell the moral obligation to prevent or render abortive, if he could, a crime that he knew was pending. And besides—his face hardened suddenly, as he moved swiftly along, evading the direct rays of the street lights, and keeping in the shadows—he had a personal account to settle with Antonio Laverto. If it had not been for the man’s damnable imposition having succeeded to the extent that it had, he, Billy Kane, would not have left the Ellsworth house to-night, and David Ellsworth would not now——

Billy Kane’s hand, in his pocket, tightened over the butt of Whitie Jack’s revolver. Unconsciously he quickened his stride.

Always hugging the shadows, his hat drawn far down over his face, giving the passers-by he met as wide a berth as possible, Billy Kane covered the short distance that separated the Rat’s den from Marco’s. He slipped into the lane unobserved, and for the second time that night crouched against the door with the broken lock. But now, mindful of the door’s tendency to squeak, he pushed it open cautiously an inch at a time. And then, with the door slightly open, he stood motionless, a puzzled and amazed expression on his face. Just exactly what he had expected to find here, he was not prepared to say—but certainly not this! A faint light came through from the door of the back room into the hallway, and from the room there came a woman’s voice that mingled a sort of pitiful defiance with a sob.