Original by Arthur RansomeAdapted by Nick WoodFather is away and mother brings Roger, John, Susan and Titty to stay at Pin Mill where they can spend the summer messing about in boats. Their adventure begins when they go out with Jim on his boat Goblin. But disaster strikes when the boat is becalmed and Jim goes ashore to fetch petrol. Fog descends over the Harwich estuary and, as the tide turns, the boat begins to drift away...