Shamus Reilly lives in County Donegal, a little mouse who has a really good heart. Through tragedy and the loss of all his possessions, he decides to move to England and live in a house with his cousins, who had moved there some years previously. However, one Danny Lamprey swaps his ticket to Oxford and instead of going to Oxford to be with his cousin's, poor Shamus ends up in Gillingham in Kent. Great courage and determination sees Shamus through in the end. Along the way he meets several new mice, dogs and other animals. Then there is Harold Turner-Broom, once a pest control agent, will Shamus and his new wife make all the way. With the help of new friends and a way of melting the most hardened heart, Shamus wins through in the end. A story that will warm any heart.