"There, there!" whispered Dr. Pye. "What do you see?"
Dr. Vinsen peered into the night. "I see nothing."
"Stand back."
Swift as thought he threw the flash-light upon the windows of Samuel Boyd's house. Then he masked the shutter and turned on the gas. Accompanied by Dr. Vinsen, who jealously watched his every movement, he stepped to the table, withdrew the film from the little machine, and developed it. And there before them came gradually into view the pictured presentment of the face and form of Samuel Boyd, standing at the window of his house in Catchpole Square.
Dr. Vinsen's face was pallid, his eyes dilated, his teeth chattered. Dr. Pye's face was thoughtful, introspective.
"Do you believe now?" he asked in an undertone.
Dr. Vinsen passed his hand confusedly across his brows.
"We had certain plans," continued Dr. Pye; "are they to be carried out to-night?"
"Not to-night; not to-night," replied Dr. Vinsen, turning towards the door.
The next moment Dr. Pye was alone.