Jams lives with his mum, dad and his best friend and biggest headache, Thimble, a hugely clever monkey who one of Dad's biggest fans. (Don't tell anyone what Thimble did with the superglue...) When Mum organises a house-swap holiday in France, Jams' one job is to remember the right house number. What can possibly go wrong, once Thimble and Dad find in the borrowed house a speedboat, a drill and a makeshift burglar outfit. But somehow Thimble always saves the day.