Walker is the owner of the Casino Royale, an airborne casino and repair station where many ships arrive for their shore leave. He is an acquaintance of Alex Row and refers to the Silvana as his "outlaw friends". When the Silvana arrives for repairs from its battle against Guild fighters, Walker provides a tip to Alex Row on the Exile artifact being sold in auction at Horizon Cave. He provides repair services for the ship again after its battle with the Urbanus.
(Source: Wikipedia)