Mausoleum

*(chapter 3.5)*

The **Mausoleum** is the alternative floor to the Depths and was added in *The Binding of Isaac: Repentance*.

Mausoleum is an occult-themed stage full of magic and cult material. Unique features of this stage include Teleporters and Grudges.

The door to the Mausoleum / Gehenna will appear after defeating the boss in The Mines II / Ashpit II or the Depths I / Necropolis I / Dank Depths I. The door will **not** spawn after defeating Mom. It costs two full hearts to enter, and ignores almost every form of damage reduction, including  and invincibility. Unlike other methods of health donation, red hearts will not be prioritized over more valuable hearts.

* The Lost,  Tainted Lost,  Tainted Jacob (In his soul form),  Tainted Soul (unless he is holding  Tainted Forgotten), and any character under the effect of  can enter the door for free.
* , , , and  can be used to open the door without taking damage.
* can be used to open the door with one bomb.
* 's effect can open the door with less damage taken than needed, or with no damage with .
* The extra characters spawned by , , and  can expend their health to open the door.
* can be used to open the door with red hearts first.

The boss of Mausoleum II is always a more powerful version of Mom. After Mom is defeated, a trapdoor that leads to the Womb II, and a sealed fleshy door both appear. Stabbing the door with the knife familiar created by  and  will cause it to open, leading to a more difficult version of Mom's Heart. Defeating Mom's Heart will cause the boss room to darken, and the trapdoor to Womb II will now lead to the Corpse.

* A  can be used in place of the Knife.
* 's effect can open the flesh door, allowing Isaac to keep the knife.
* If Isaac exits the Boss Rush room after 25 minutes have passed, there is a chance that the flesh door will change positions to the wall where the boss rush door was, causing Isaac to "come out" of the flesh door and leaving it open, allowing entry without the knife.
* After this special version of Mom's Heart is defeated, any Item or Pickup that was left behind anywhere on the floor will disappear (including Shop items, Angel Room/Devil Room items, etc.): the floor will be empty.
	+ Therefore, make sure not to leave behind something that you might want to use after this floor. The strategy consisting in teleporting outside of Mom and Mom's Heart to retrieve something that was left behind after fighting them is **not** viable here.
	+ If a Shop Restock Machine is used within the now-empty shop, it will restock the shop as normal.
	+ If the effect of  is invoked after the special version of Mom's Heart is defeated, the Curse of Darkness-like effect will remain on the newly generated floor. Additionally, no items will naturally generate in rooms where they would have. After the player defeats Mom again, there will be no flesh door, and the trapdoor to Corpse will appear.
	+ The alternative floor to Mausoleum is Gehenna. It is unlocked after all bosses from this floor have been defeated.

## Trivia

* In *Antibirth*, fully constructing The Knife required 3 Knife Pieces, with the third appearing in Mausoleum II. For Repentance, however, the third piece was removed, and the completed knife only requires the player to obtain two pieces from Downpour and Mines.
	+ Also in *Antibirth,* there was a mechanic where somewhere on the floor, there was a special Teleporter that usually required solving a puzzle, having flight, or using pickups to access. This Teleporter led to a second section of the floor, a cluster of rooms with enemies and a few random special rooms. Since this second area was on the same map as the main part of the floor, it could also be accessed by using the Red Key enough times to reach it, or by teleporting to it with other means. Both floors of the Mausoleum had this feature, and in Mausoleum II it was required to go there to solve a puzzle in order to unlock Knife Piece 3. However, like Knife Piece 3, this mechanic was also removed in Repentance.
* The Visage was originally a Mausoleum boss in *Antibirth*, but it was changed in Repentance to appear on Mausoleum's alternate floor, Gehenna. Its appearance was also updated from grey and purple to black and red to reflect this.
	+ This might have been because of Gehenna's "torture chamber" theming, which The Visage complements more so than Mausoleum's occult theming.
* Mausoleum is referred to on Isaac's Last Will as "Some Cursed Place".