"Follow that green car ahead," she directed tersely, climbing in. "Don't let it get out of your sight."
At the first corner they were held up by a light which was changing from caution yellow to red. Risking arrest, the taxi driver crashed it.
The green car ahead had picked up speed. It weaved in and out of traffic in a dangerous manner, driven by a man who was both skillful and reckless.
The pursuit led into the hilly, crooked streets upon which the older section of Belton City had been built. As they raced down first one narrow street and then another, turning corners at a breathless speed, Penny suspected that the man had become aware that he was being followed. Her driver had increasing difficulty in keeping him in sight.
"The right hand turn!" Penny cried as the taxi-man hesitated at an intersection.
They tore down a dark, twisting street at a break-neck speed. Suddenly the driver slammed on his brakes. The thoroughfare had come to an abrupt end.
"It's a dead-end," the taximan said in disgust, turning the cab around. "He couldn't have come this way."
"I'm sure he did," Penny insisted.
The street was short and she could see its entire length. The green car had vanished.
There were no houses or garages into which the automobile might have turned. On either side of the street stood factory and manufacturing buildings.