Obstreperous test pilot Tuck Pendleton (Dennis Quaid) volunteers for a miniaturisation experiment that should see him and his ship injected into the bloodstream of a laboratory rabbit. Instead, thanks to some industrial espionage gone badly wrong, he finds himself inside hypochondriac no-hoper Jack Putter (Martin Short). Aided by Pendleton’s ex-girlfriend, journalist Lydia Maxwell (Meg Ryan), and guided from within by Pendleton himself, Putter must overcome his inhibitions, thwart the villains and recover the microchip necessary to extract the ship before Pendleton’s oxygen runs out.
