"Did you see an automobile without headlights come this way?" the driver asked tersely.
Penny was only too glad to offer information.
"It turned into this dead-end," she began.
The officers did not wait to hear more. With a roar, the cruiser was off again. It reached the end of the street and halted because it could go no farther.
Penny, bent upon missing nothing, followed as fast as she could.
By the time she reached the radio cruiser one of the officers had alighted. He was looking carefully about. Sighting Penny, he walked over to her.
"Say you! I thought you told us that car came this way."
"It did," Penny maintained staunchly. "I saw it go to the very end of this street. The lights flashed on for an instant. Then the car seemed to vanish. I think it must have gone into that building."
She indicated the Hamilton Manufacturing Plant. The officer surveyed it briefly.
"Don't kid me!" he snapped. "Only a Houdini ever went through solid walls!"