Episode One, Floor One is the first level of Wolfenstein 3D episode "Escape from Castle Wolfenstein" and the very first level of the game. It begins with BJ standing in front of the body of a Guard he has just killed. The secret level, Floor 10 is accessible from this level. The level later appeared in Doom II on MAP31 as a secret level. There is an additional secret in Doom II on the right side of the map, in the area with the dogs, that does not exist in this level. The way to the secret exit to Floor 10 was replicated exactly for access to the super secret level of Doom II (MAP32).