In the third screen adaptation of his best-selling 1916 novel, acclaimed writer Booth Tarkington focuses on the mischievous Penrod (Billy Mauch) and his pal Sam (Harry Watson) in this junior league detective caper that pits the boys against dangerous murderers. Penrod and Sam spring into action after a member of their junior G-Men Club loses his mother in a bank shoot-out. Since the club is pledged to solve crimes and bring crooks to justice, the boys set out to capture the killers - but are instead captured when the killers hide out in their clubhouse. After Penrod's rival, Rodney, is also captured, the three boys join forces to hatch a daring plot and outsmart their captors. This popular film inspired two sequels: Penrod and His Twin Brother and Penrod's Double Trouble, both of which starred Billy Mauch and his twin sibling, Bobby.