An introverted songwriter Mark Deveraux (Randy Quaid) inadvertently brings millions of wisecracking, joke-loving little green Martians to Earth when he writes a theme score for a sweet love story. But the music is accidentally broadcast to the galaxies by his radio technical girlfriend. When the Martians begin to arrive, the chaos begins. Mars’ greenest inhabitants have interpreted the music as an open invitation to “come on down”—and billions of them do. Based on the novel written by Frederic Brown.