Trixie wins the position of Speed's assistant in the No Limit World Race. Before the race begins Inspector Detector and his officials search each entry looking for $50 million in stolen gold bars. The Mammoth Car enters the track. Cruncher Block gives the Inspector a tour, yielding no trace of the gold.The race begins. The Mammoth Car forces everyone off the road. Speed is suspicious. To discover the Mammoth Car's secret, he equips the homing robot with X-ray film able to penetrate metal