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.
"I'll be going asleep from that vapor myself in a minute, if I'm not careful," he told himself. "I've hardly any more of the stuff. It's a good thing they're all down and out!"
He lifted the unconscious guard and carried him to one side, where he could not be seen from the entrance. Then he ran through the corridor and threw the light switch again, so that those outside would think everything was all right in the interior.
Then he ran to the basement door, hurried down the steps, went to a big electric switch on the
