E1M10: Sewers is a secret map exclusive to the Xbox version of Ultimate Doom, included with the Xbox Collector's Editions of Doom 3 and Doom 3: Resurrection of Evil. It can be accessed in Knee-Deep in the Dead from E1M1: Hangar, and contains several textures and monsters not originally featured in the episode, such as Lost Souls and Cacodemons. Barons of Hell also appear as normal enemies, even though they were originally only fought in the episode as bosses in E1M8: Phobos Anomaly. It uses the music track "I Sawed the Demons."