Mike and Chip take part in good deeds -- Mike goes with his fellow U.S. Air Force Reservists to deliver ten thousand dolls to children in a South American disaster area. Mike meets a mute girl and tries to collect money for an operation she desperately needs. Meanwhile Chip becomes household slave of the demanding Mrs. Sowerby.

Tramp appears to be the ideal choice sor a starring part in a Hollywood film, and accompanied by Bub, Robbie and Chip, he goes to the tinsel town capital of the film world for an audition and screen test for a feature called 'Moon Dog'.