Two twelve-year-old boys, Romeo and Gavin, undergo an extraordinary test of character and friendship when Morell, a naive but eccentric and dangerous stranger, comes between them. Morell befriends with the two boys and later asks them to help him pursue Romeo's beautiful elder sister. He gradually becomes more violent after she rejects him.

In a typical English working-class town, the juveniles have nothing more to do than hang around in gangs. One day, Alan Darcy, a highly motivated man with the same kind of youth experience, starts trying to get the young people off the street and into doing something they can believe in: Boxing. Darcy opens a boxing club, aiming to bring the rival gangs together.

Mischief' is the latest addition to a pony trekking stable. Davy looks after him during the school holidays and discovers that 'Mischief' was once a circus pony and reacts to the sound of music. This leads to incidents full of excitement and suspense.