??? (Floor)

*(chapter 4.5)*

 This article is about the chapter. For other uses, see ??? (Disambiguation).
**???**, referred to as **Blue Womb** or **Dead Womb** in the OST, is a chapter added in *The Binding of Isaac: Afterbirth*. It is unlocked by defeating Mom's Heart for the 10th time.

It is accessed by defeating Mom's Heart or It Lives within 30 minutes. Leaving and re-entering the Boss Room after the timer has reached 30 minutes will make the entrance to ??? disappear.
 If the player is fast enough, both Boss Rush and ??? can be completed in a single run.

It contains the following:

* Four Locked Chests in the main room.
	+ Unlike the ones in the Chest, these are just regular golden chests and don't guarantee an item drop.
* Two locked Treasure Rooms, both of them offering two choices of items as if  was active.
* A Shop that always contains 6 goods for sale, even if Shop Upgrade Lvl. 4 has not been unlocked.
* A 2x2 boss room that contains Hush.
	+ The door leading to the boss room might blend in with the northern wall but will slide away upon approaching it.

It is advised to only enter ??? with very powerful items and/or a set of good dodging skills because Hush ranks amongst the most difficult bosses of the entire game.

After Hush is defeated, one of two things will happen:

* If this is the first time Hush has been defeated, a giant golden chest will appear in the middle of the room. Jumping into it ends the run and gives ending 17.
* If Hush has been defeated before, a trapdoor and a beam of light leading to Sheol or the Cathedral will appear.
	+ If Hush has been defeated before but Sheol and the Cathedral have not been unlocked, the giant golden chest will appear instead.
	+ Additionally, an exit will spawn in the corner of the room, containing a portal leading to The Void.

## Notes

* This floor cannot be skipped with  or ; neither will work.
	+ The floor can be skipped if a Black Market or I AM ERROR room is found, and will always take the player to Sheol.
	+ will skip the floor, and always take the player to Cathedral.
* ??? has its own Devil Room/Angel Room which can be reached via a Red Chest or a .
* ??? doesn't have any Secret Room or Super Secret Room.
* Using  or holding  will open the entrance even if the time limit has expired.
* Rocks contained in ??? have a significantly increased chance of spawning a Crawl Space when destroyed.
* creates exclusive room layouts that contain the following enemies:

 Hush Fly | 296.0
 Blue Gaper | 297.0
 Blue Boil | 298.0

* Despite red rooms being able to be created, no Ultra Secret Rooms appear, even when using .

## Trivia

* The displayed name of the chapter is ???, but the chapter is referred to as Blue Womb by the achievement, using the same logic as the character  ???.
* The character ??? and the chapter ??? have the same unlock requirements.
* ??? is unique as the only chapter that can be optionally done between mandatory chapters.
	+ It is mandatory, however, to complete this chapter to unlock The Void.
	+ It is also mandatory to complete three times to unlock Downpour, as well as the rest of the alternative chapters.
* ??? is the smallest chapter, only containing 6 normally accessible rooms.
	+ Home ties with ??? in terms of having 6 normally accessible rooms.
* In Isaac's last will, ??? is referred to as "some barren place".
	+ This may be a reference to the fact that infertile women were historically referred to as "barren".
* ???'s icon on the progress bar is actually a recolor of the Womb's.
	+ Similarly, the trapdoor leading to ??? is a recolor of the trapdoor leading to the first and second floor of Chapter 4.
* There is an unused version of ???, which uses the textures for the Basement and has the filter seen in The Ascent. It can be accessed by typing `stage 9c` in the Debug Console. The void portal in this version of ??? is replaced by a cobweb.

## Gallery

* Concept for ??? on the lower left side by Edmund McMillen.

## Music

* The stage's music is called *Mater Prope* or *Nativitate*.
	+ These names are in Latin and could be translated to "Almost Mother" and "With Birth" / "Due to Birth" / "At the Time of Birth" respectively.
* The tracks that play during the battle against Hush are called *Ascension* (the ??? boss fight music; played during Hush's first phase, which is similar to the ??? boss) and *Morituros* (during the second phase).