Great Aunt Dymphna drew herself up. 'You have a whole wing of the house to yourselves. This magnificent kitchen. The glorious world outside to play in. All that the earth brings forth to feed you, and you stand there asking foolish questions until my head reels. Help yourselves, children, help yourselves.' Then, flapping her cloak as if to shoo off a clutter of chickens, she was gone.

The four Gareth children lead a quiet life in a London suburb, but when their father, an epidemiologist, gets ill abroad, their mother has to leave to take care of him.

The children go to stay with an eccentric relative they have never met - Great Aunt Dymphna, who lives in a ramshackle house in Ireland. Here, they are not only expected to look after themselves, they also discover they have company - a mysterious boy who announces that his is on the run. Irritating as he is, the children agree to hide him from his pursuers - but who are they? And who is the boy? The children are determined to find out.