The five others were clustered about the card table. The Black Star's man crept forward and took a vapor bomb from beneath his coat. This was the perilous moment, he knew. This particular bomb was a delicate one that would make no noise as it exploded. But unless the vapor struck into the nostrils of the five men, disaster might come. If one of them escaped unconsciousness for a moment, he would be able to give the alarm.
Another bomb came from beneath the coat. The first one was hurled to the marble floor at the back of the five men. The second followed it.
Clouds of vapor arose. The Black Star's man held a sponge to his nostrils, flashed his torch and watched. It had worked—the five men were staggering—had fallen!
He had swift work to do now. At any moment the guard might return with the engineer, or the other guard come from the front door. He knelt beside the first man, and drove home the point of the needle. He worked in the dark, for it was safer that way. One by one he drugged them, and then he darted noiselessly toward the door that led to the basement.
He was just in time—the guard and engineer were coming up.
"Guess it's a fuse," the guard was saying. "Lights on the upper floor are still burning."
They stepped into the dark corridor, and the guard called for one of the policemen to flash his torch. The Black Star's man stepped up close, and again the vapor gun was discharged. They staggered and fell.
The needle was used again, and then he darted toward the entrance. The guard there had reported to the one outside, and was returning.
"Hurry up with those lights!" he shouted.
He gasped; collapsed. The Black Star's man caught him and let him down to the floor. He was holding the sponge to his nostrils again.