Successful racecar driver Capua (Paul Newman) falls in love with Elora (Joanne Woodward). The two marry and settle down with Elora's 13-year-old son Charley (Richard Thomas). The honeymoon is short-lived as Capua must spend his time away from home on the racing circuit. Soon the racer's luck begins to change as his main rival Luther Erding (Robert Wagner) begins to best him at every race. Capua has a one-track mind and realizes too late that his wife is being lapped by the rival racer not only on the track but in the bedroom as well. He comes home to find his wife in bed with Luther, and he promptly leaves. Young Charley hitchhikes across country in an attempt to bring the couple towards a reconciliation. Richard Thomas, who would later star in the television series "The Waltons," makes his film debut. Spectacular footage from Elkhart Lake, Wisconsin and Indianapolis is used, including a 17-car pile-up. Cameo appearances are made by racers Bobby Unsur and Tony Human. After doing all his own driving during filming, Paul Newman would develop a lifelong passion for auto racing beginning with this film.