Remember the Humble Guinea-Pig

A number of animals are killed at the Bellington Zoo and suspicions point to a keeper being responsible, it later transpires to be the work of a suspended prison officer who once worked at the zoo. Paddy is offered the post of head keeper at the Bellington and Liz masterminds an education centre at the zoo. Meanwhile Donald fights tooth and nail to prevent Challon using dubious methods to make money using the dolphins at Manford Safari Park.