Rick Heller, a young troublemaker, frequently finds himself in problematic situations. In an effort to steer him away from mischief, his mother assigns him the task of cleaning the enclosure of a gorilla named Katie, whom she is instructing in sign language. However, when Katie’s owner decides to exploit her as a sideshow attraction at a flea market, Rick resolves to rescue her. He embarks on a daring adventure to help Katie escape and leave the country.