With the Doctor condemned to death by the caretakers and their bizarre rulebook, Mel faces cannibalistic OAPS. Is Pex going to be the true hero of Paradise Towers ?

Mel and Pex play cat and mouse with the lethal cleaner robots while the Doctor and the surviving Kangs learn all about Kroagnon the Great Architect.

Meeting up at the pool, the Doctor leads the surviving Rezzies, Kangs and Caretakers as they draw the line together on the 245th floor against the systematic cleansing of all life by Kroagnon and his robotic Cleaners.