The Protean was a Strike Cruiser of the Salamanders Chapter. The vessel was commanded by the Firedrake Nu'mean. The vessel was lost in a warp storm after an attack by Eldar. Nu'mean was the only survivor. Nearly a century later the ship returned from the warp as part of a large Space Hulk. Herculon Praetor led two squads of Firedrakes including Tsu'gan and Nu'mean to kill an Eldar Farseer in stasis aboard the Protean. After fighting off waves of Genestealers they were ambushed by the Night Lords. Despite losing several marines, including Nu'mean, the Firedrakes eventually succeeded in killing the farseer. However, Apothecary Emek was badly wounded.