Gilligan (Bob Denver), the Skipper (Alan Hale Jr.), the Howells (Jim Backus, Natalie Schafer), the Professor (Russell Johnson), Mary Ann (Dawn Wells), and Ginger (Judith Baldwin) have been shipwrecked for 15 long years, but when a decaying Soviet satellite crashes on the uncharted tropical island, their dreams of rescue finally come true! The Professor builds a barometer after finding a key component inside the downed sputnik, and with that device the castaways learn their island home is about to be struck by a massive tidal wave. In desperation, they lash their bamboo huts together, but the structure is swept out to sea where Gilligan starts a disastrous cooking fire. Fortunately, the smoke attracts the attention of rescuers, and the castaways return to Hawaii. They soon discover that readjusting to life in civilization will not be easy, and complicating matters are a couple of Russian spies in pursuit of the satellite part that Gilligan has turned into a necklace!