When his younger brother, Steve (Del Erickson), is killed racing a hot-rod, Jeff Northup (John Smith) 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 (Chuck Connors), 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 (Mark Andrews), a newcomers, makes a play for Jeff's girlfriend, Lisa Vernon (Lori Nelson). 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.