The Free Traders are an insular, clannish, matriarchal culture who live their lives in space, traveling from world to world trading. Thorby is adopted by the captain (thereby gaining considerable shipboard social status) and adjusts to the culture of the traders, learning their language and intricate social rules. The advanced education provided by Baslim and the fast reflexes of youth make him an ideal fire controlman; Thorby saves "Sisu", destroying a pirate craft. His immediate superior, a young woman named Mata, begins to view him as husband material, tabu by Free Trader custom, so she is transferred to another ship.