MAP31: Doorway to Quake is the secret map of Requiem. It was designed by Iikka Keränen, and uses the music track "Breach of Madness" by Mark Klem, also the megawad's text screen music. It is a remake of E1M6: The Door to Chthon from Quake, originally designed by American McGee, and notably features a faked sector-over-sector effect, as well as a simulated sliding door. This level contains a secret exit leading to MAP32: Bitter Herb. Completing this level through the normal exit takes the player to MAP16: Escape from Chaos.