Living with his family in Baltimore, 9-year-old Lewie Penrose (Jackie 'Butch' Jenkins) claims that he can converse with horses-and also pick the winners of upcoming races. When it appears as though Lewie is telling the truth, he attracts the interest of gambler Rich Roeder (Charles Ruggles), who needs a "sure thing" in the upcoming Preakness Stakes. Meanwhile, Lewie's older brother John (Peter Lawford) carries on a romance with the lovely Martha (Beverly Tyler).