Binding of Isaac: Rebirth Wiki

Added in Afterbirth
Disambig.png 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 Mom's Heart for the 10th time.

It is accessed by defeating Mom's Heart or It Lives 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. The boss of the floor is always Hush Hush.

It contains the following:

  • 4 Locked Chests in the main room.
    • Unlike the ones in the Chest Chest, these are just regular golden chests and don't guarantee an item drop.
  • 2 locked Treasure Rooms, both of them offering two choices of items as if More Options More Options was active.
  • A Shop that always contains 6 items, 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 Sheol or the Cathedral 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 Added in Afterbirth † Portal Portal leading to The Void The Void.


Boss Hush portrait.png


Entity ID Description
Blue Conjoined Fatty
Blue Conjoined Fatty
257.1 Slowly walks towards Isaac and occasionally farts out a homing Ipecac shot at Isaac.
Hush Fly
Hush Fly
296.0 Gathers with other Hush Flies to form certain patterns. If spawned by Hush Hush, can chase Isaac or orbit Hush. Deals contact damage.
Blue Gaper
Blue Gaper
297.0 Walks towards Isaac, dealing contact damage.
Blue Boil
Blue Boil
298.0 Stationary enemy that decreases in size when hit, but regenerates to its full size until fully destroyed. Fires 1-3 blood shots towards Isaac when fully swollen.


  • 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.
    • Added in Afterbirth † It is mandatory, however, to complete this chapter to unlock The Void The Void.
    • Added in Repentance It is also mandatory to complete three times to unlock Downpour Downpour, as well as the rest of the alternative chapters.
  • Removed in Repentance ??? is the smallest chapter, only containing 6 normally accessible rooms.
    • Added in Repentance Home 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 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.



???'s music is called Mater Prope or Nativitate. These names are in Latin and translate to "Almost Mother" and "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).

Binding of Isaac: Afterbirth OST


Bug Bug! Removed in Repentance Attempting to open the door leading to Hush's room while holding a Golden Key will cause Isaac to walk through the door without opening it, immediately beginning the Hush fight.