My Three Sons (1960)

S8E23 Dear Enemy

Robbie heads off to Camp Roberts for a two-week stint of military reserve training. Meanwhile, Steve grows worried when he discovers a card from Charley, indicating that he and the boys camping at Yosemite intend to pay Robbie a visit. Unfortunately, Steve arrives too late to stop them, and one by one, each family member accidentally finds themselves captured as military prisoners.