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.