According to the sales brochure, Paradise Towers is a Utopian blueprint for community living, with its fabulous architecture and state-of-the-art facilities. The perfect place for Mel to take a leisurely swim, in fact. But when the TARDIS arrives, the Doctor and his companion discover that the futuristic tower block has fallen into ruin, and a series of unexplained disappearances have the tenants living in fear. As gangs of teenage girls run wild in the hallways, a squad of bureaucratic Caretakers struggle to retain control. To keep the citizens of Paradise Towers safe, the Doctor must confront the resident evil lurking in the basement.