Had they done so, they might have found a man who was hiding there. But it was not the man they sought.
It was Spotter. The shrewd hawk-eye of the under world had been in concealment almost immediately after leaving Doc Birch. He had scented trouble the moment he had left the house, and he had taken refuge in the improvised hiding place just as the Federal agents had arrived.
He had seen the first man enter through a cellar window. He had heard the shots. He had seen the lights in the windows over the pawnshop.
Moreover, he had seen a policeman enter the alley. He had seen the officer come out accompanied by a secret-service man. He had seen the policeman reenter the alley. While Spotter had still waited, he had seen two agents go in to join the policeman.
Now all three had departed, and Spotter was ready to leave.
He was somewhat worried about Doc Birch. The side door that went upstairs above the pawnshop was out of view. He had not seen the removal of the prisoner.
Yet Spotter was ever cautious. He resolved to wait a few minutes longer. His eyes were glued to the alley that led behind the house. While he stared, he saw a movement in the shadows. He gazed into the blackness, almost unbelieving.
Then, beneath a light across the street, a figure came momentarily into view. It was a figure cloaked in black; a shape that merged with inky darkness and vanished with amazing suddenness.
Spotter’s blinking eyes followed the form down the street. They saw nothing for a moment; then they observed a shadow on the pavement. It swept by a light, then disappeared. It showed again, farther away. Then it was gone entirely.
Spotter trembled as he crouched behind the boxes. He gulped and repressed a terrified gasp.