Percy, an adventurous fieldmouse, lives under a flower pot at Springhill Farm with his brothers and sisters. He is keen to explore and ventures into the farm yard and the kitchen garden of the farmhouse. Mr Horace Cumber, the gardener and the farmer's children, Alexander aged 10, Archie aged 8 and 6 year old Annie, are working on the garden with their dogs Jock, a Jack Russell Terrier and a sheepdog called Nan. Percy is attacked by two blackbirds fighting over a worm. To escape he runs for his life to the nearest bolthole - up Alexander's trousers, who clutches at his trousers, trapping Percy inside. Alexander then runs into the farmhouse shouting "I have a mouse up my trousers", and Percy's adventures begin, as he is chased by the farm dogs and the farmer inside the farmhouse in a chaotic mouse hunt.This is the first of four stories of Percy's adventures at Springhill Farm.