Jack Holborn, 14, was abandoned as a baby on the steps of Holborn Church in London. On his arm he wore a leather band with the name Jack on it, and that's how he got his name. Not wanting to live with a foster family, Jack tries to get work on a sailing ship. He signs up for Captain Sharingham's Charming Molly. It immediately becomes clear to him that the captain knows more about Jack's parentage because he recognizes the leather strap, but Sharingham won't say anything. Jack wants to do everything he can to find out who his parents were and hides on the ship. When he tries to steal a ham, he is discovered, but the ship is already on its way to Africa. The pirates are on a treasure hunt and Jack has little choice but to adapt. Will he ever learn the truth about his parentage from Captain Sharingham?