The TARDIS crew take a holiday, but the Doctor encounters an enemy he thought long since dead. A plan to build a nuclear power station in Cardiff City disguises an alien plot to rip the world apart. And when the Doctor dines with monsters, he discovers traps within traps.

When a member of the slitheen family survives, she tries to rip apart planet Earth by using the rift that was sealed in Cardfiff many years ago by the Gelf. But the Doctor soon diminishes her plans and she is left with nothing. All of her family was destroyed in the Downing Street blast. The doctor arrests the Slitheen and takes her into his custody, ready to take her back to her home planet, where she will probably be executed. As a last request, he takes her to dinner. Whilst there the rift starts to open. They both panic and the doctor undoes the handcuffs he has strapped to her. When they get back to the TARDIS she holds Rose hostage and tries to get away, but she inadertently looks into the heart of the TARDIS. This reduces her back to an egg, giving her a second chance of her life.