In August 1912, three friends set out on an adventure. Two of them come home. Tom, Jimmy and Itzhak have grown up together in the crowded slums of Walworth. They are used to narrow streets, the bustle of East Lane market, extended families weaving in and out of each other's lives. All three boys are expected to follow their father's trades and stay close to home. But Tom has wider dreams. So when he hears of a scouting trip, sailing from Waterloo to Sheppey and the mouth of the Thames - he is determined to go. And Itzhak and Jimmy go with him.