Chronically embarrassed by her family's over-the-top Christmas celebrations, a teenage girl hatches an elaborate plan to avoid her parents when her long-distance boyfriend plans a visit.

A troubled family move to an isolated house, and find and adopt a couple of cats already in residence. These are not the only occupants however...

Basil, the rodent Sherlock Holmes, investigates the kidnapping of a toy maker and uncovers its link to his archenemy, Professor Ratigan.