When his younger brother, Steve, is killed racing a hot-rod, Jeff Northup blames himself for the accident since he had built the car for his brother and had encouraged him to race it, with other boys on a special course provided by police detective Ben Merrill, who is working to reduce the city's hot-rod fatalities by providing supervision for the dangerous hobby. Jeff withdraws from participating in races on Merrill's course and, without his leadership, revert to racing on the streets. "Bronc" Talbott, a newcomers, makes a play for Jeff's girlfriend, Lisa Vernon. Eventually, the taunting-Talbott forces Jeff into a race which results in the death of a bicycling child, and evidence seems to indicate Jeff was at fault.