the words were spoken aloud in a thick, jerky voice, and it seemed to be all that stone could do to keep his clutching hands from his senseless partner’s throat. doubtless he remembered the rascally doctor’s promise that crawford would know nothing about it all when he woke in the morning, and that was probably what stayed his hand.

had the detective been in any doubt of the man’s condition, it would have vanished then, and stone’s irresponsibility was even more evident when he turned away from the bed, and the light from the transom struck his face. it was wrinkled into a mask of maniacal triumph, and the glare in the eyes was more like that of a wild animal than of a human being.

nick held his breath for a moment. stone was heading directly toward the bathroom, apparently with the idea of washing his hands after handling the drugged sponge. if he should enter there, discovery would be inevitable, and the detective would have a crazy man to handle—a task which even he did not care to contemplate.

presently, however, when stone was only four or five feet from the door of the bathroom, he suddenly wheeled about and recrossed to his own door, through which he disappeared. his shrewdness had evidently suggested the desirability of performing the necessary ablutions in his own room.

nick relaxed when the danger was removed, and after waiting for perhaps five minutes following the closing of the connecting door, he stole from his hiding place and sought crawford’s bed. no odor of the drug had reached his nostrils in the bathroom. it was evidently so volatile that it had been quickly dissipated in the air. the detective knew its nature, however, for he had sniffed at it in stone’s room. he was aware that it was all that doctor follansbee had claimed for it, and that, under ordinary circumstances, it would work no permanent harm; but what he did not know was its effect on winthrop crawford. crawford seemed to possess a rugged constitution, but his heart, for instance, might be weak. nick wished to make sure that his new friend’s condition was normal before he left the room.

his examination, for which he did not need a light, was satisfactory. the drug had plunged crawford into a profound sleep, but there was nothing to indicate that the effects would not pass away in good time, leaving him in his usual health. as for the injection, that meant nothing, so long as the serum which follansbee had provided was now reposing in nick’s fountain pen. to be sure, the hasty cleaning of the syringe might not have removed all traces of the serum, but the detective had done his best, and knew enough of such things to feel sure that the consequences, if any, would not be serious. crawford might possibly have a slight touch of the disease, whatever it was, but it was not likely to amount to much.

the detective straightened up a little, listened, then produced his pocket flash light and turned the rays on crawford. it was an easy matter to find where the puncture had been made, for a tiny globule of blood stood out on the tanned skin of the man’s arm. nick stooped lower and took a bit of the flesh between thumb and finger. he succeeded in squeezing out a few drops of water and blood, which he carefully wiped away.

“you’re safe enough, my friend,” he thought. “anyhow, i’ve done my best for you, and to-morrow will decide whether you’re still foolish enough to refuse to guard yourself against the attacks of that madman, or whether you’re willing to listen to reason and let me put him where he belongs.”

having done all he could for the time being, he straightened up and stood in thought for perhaps half a minute, uncertain of his next move. he had heard enough of the conversation between stone and follansbee to know that the latter had planned for the miner to join him after the diabolical injection had been made. that meant that stone would soon venture forth again, doubtless by way of the fire escape, and there was no knowing what moment he might appear at his window. consequently it would be extra hazardous for nick to venture out on the platform and try to pass stone’s room.

he decided to wait for a few minutes, and to return to the bathroom to do so, for stone might take it into his head to come back into crawford’s room for some reason.

in a short time he had the satisfaction of hearing stone’s window go up and then down again after the man had passed through. his alert ears caught a few slight sounds on the fire escape, which told him that the miner had begun to descend. he had planned to follow, if possible, owing to his realization that follansbee might be playing a double game, and was quite capable of making away with stone as well as crawford. he had brought along his shoes for that purpose, having suspended them about his neck by means of the laces, and during the last few minutes he had put them on in the bathroom.

it occurred to him now, though, that the difficulties were even greater than he had looked for. it would not do for the floor clerk to see him emerging from crawford’s room, for she would naturally become suspicious at once, and, not knowing his identity, would cause a delay before an explanation could be made. on the other hand, he could not follow down the fire escape until stone had disappeared from the courtyard, and by the time he could reach the near-by bank, where follansbee was to be waiting, the car would doubtless have carried the two conspirators off.

moreover, he had known all the time that there was small chance of following the machine at that hour. he certainly could not do so on foot, and even if he had arranged for another car to be in waiting in the neighborhood, there would be considerable delay in reaching it. on the whole, therefore, he reluctantly decided to return to his own room, and call it a night’s work. it was not that he trusted follansbee any more, but merely that he thought a few hours’ delay would not entail serious consequences to james stone.

he did not dream, however, of what was in store for the ex-miner.