It chronicles the scrapes of the church mice as they try to find a home for a stray dog, a quest which soon comes to involve an easily lost diamond ring.

The mice initially dismiss his attitude as 'anti-dog talk', but soon come to regret their decision after Percy eats their entire week's cheese supply, leaving them to subsist on the discarded scraps of food which are thrown over the churchyard wall.

Seeking to find Percy a new home as quickly as possible, the mice and Polly decide to introduce him to her wealthy parents who live in a large house nearby.

Desperate to have Percy off their hands in order to begin eating adequately again, the mice infiltrate the jeweller's shop at night and retrieve the ring, but are promptly arrested by the police.

Just after finding the ring, Percy is attacked by the jackdaw and falls off the tower, causing Sampson and the mice (who are holding the other end of the stole) to be pulled off with him.