The three of them pounded up the stairs to the room where Russ had heard the thump. There was nothing on the floor. They searched the room from end to end, then the other rooms. There was no wrench.
At the end of an hour Greg went back to the main laboratory, brought back a portable fluoroscope.
"Maybe this will do the trick,” he announced bleakly.
IT did. They found the wrench inside the space between the walls!
Russ stared at the shadow in the fluoroscope plate. Undeniably it was the shadow of the wrench.
"Fourth dimension,” he said. “Transported in time."
The muscles in Greg's cheeks were tensed, that old flame of excitement burning in his eyes, but otherwise his face was the mask of old, the calm, almost terrible mask that had faced a thousand dangers.
"Power and time,” he corrected.
"If we can control it,” said Russ.
"Don't worry. We can control it. And when we can, it's the biggest thing we've got."