Bill Buckle has had a dream--he wants to buy back the family fishing boat, the Cascade, which the family had to sell years ago to pay for his father's funeral. However, the boat is now owned by a trio of fishermen, and their plans for the boat don't coincide with Bill's at all.

The Battersea Bats are a gang of four kids who have their den in an abandoned building near the Thames, and they have a plan of action in mind because in about a week there is a soapbox derby being held, a contest they mean to win.