“He did not fire a gun,” answering the policeman, Grover clarified his deduction. “But—think! Where in that office could a man be, and not have the camera register his presence? Granting that he could lift the gun above his head and still keep it out of sight of the lens.”
“Can’t be,” cried Potts.
“Can.” Roger almost shouted in his interest. “He could crouch on the side of the desk toward Astrovox, and shoot at the man behind the desk, and the puff of smoke would shoot out toward the man.”
“Yes,” Grover agreed, but suddenly he jumped as his nerves reacted to a new idea.
“But—wait! A gun at that angle could not discharge a bullet to smash the inkwell.”
They stared, and then admitted his sensible reasoning.
“Back where we started,” growled the detective.
“It is a ‘composite’ picture, perhaps,” said Ellison. “You know—one part taken at one time, another exposed elsewhere, or at another time.”
“Possible, not probable,” volunteered Doctor Ryder. “In double-exposures, wouldn’t the smoke be—I don’t know the phrase——”
“Not in register,” cried Roger. “It can’t be double- or triple-exposed. Everything is all together, the smoke over the desk, and the men properly distinct.”