MAP06: The Crusher is the sixth map of Doom II. It was designed by American McGee and uses the music track "In The Dark". The monster Revenant debuts in this map; also, if the game is played on skill level 3 or lower, the Hell Knight - who only debuts in the previous map if the game is played on skill levels 4 and 5 - will also be introduced; in such difficulty levels, the Spiderdemon also returns from the original Doom. The map is named for the giant crusher in the large room near the starting area.