Jeanne is a shy young woman who works the graveyard shift as a cleaner at an amusement park. Her mother wants her to meet a man, but Jeanne prefers tinkering in her bedroom with wires, light bulbs, and spare parts, creating miniature versions of theme park rides. During her late-night shifts she begins spending intimate time with the alluring new Tilt-A-Whirl ride that she decides to call Jumbo.