No one heeded their cries.
Detective Cardona and Professor Biscayne were in the most distant part of the apartment. With two thick doors between, the shouts could not be heard.
They were not even audible to The Shadow, who stood in the outer room. He, too, was far away.
He was standing by the open door of the laboratory. Peering from the gloom, his keen eyes were studying the men who were searching there.
The eyes of The Shadow gleamed.
For the brain behind them knew!
CHAPTER XXIII
MURDER WILL OUT
JOE CARDONA had found the drawer marked E. From it, he was drawing papers that appeared to be what Professor Biscayne wanted.
Just as Cardona was about to call to Biscayne, his eyes noted an envelope that was among the papers in his hand.