- Combines with Knife Piece 1 to form a knife familiar that launches itself in the direction Isaac shoots, dealing 25 damage to and piercing enemies it hits.
- Launching it at the red door at the end of Mausoleum/ Gehenna II will open the door, destroying the knife in the process.
How to Acquire
- In Mines/ Ashpit II, there is a tall room with a broken minecart track. Scattered across the floor are three yellow buttons that will repair pieces of the track. Once all buttons have been pressed, the minecart becomes rideable, which will take Isaac to an abandoned area, with Knife Piece 2 at the end. Picking up the Knife Piece will trigger a chase sequence in which Mother's Shadow will pursue Isaac through the corridor. Getting to the end of the area will seal it off.
- While in the abandoned area, all of Isaac's items and consumables are removed except for Knife Piece 1. Extra Life items will not activate despite still visually appearing beside the health bar. However, any items with reroll protection, such as The Polaroid and Dogma, will still function as normal. Technically, the knife pieces themselves only work in this area because they also have reroll protection.
- This room, as well as the buttons to reach it, will only be generated if Knife Piece 1 was already collected.
- The buttons can be bypassed with flight and 2 bombs to destroy the door.
- It is possible to find a crawlspace as normal in this area, which will be the same crawlspace as any other generated on the normal floor. Entering the crawlspace will allow Isaac to use his normal items and consumables, but Mother's Shadow will also be present. Using any teleport card or item will teleport Isaac to a random room on the abandoned area map. Any items obtained while in this crawlspace will remain upon leaving the area, but will not be able to be used while in the abandoned area.
- It is possible to softlock the run by entering a crawlspace with the key needed to escape the room. Upon leaving the crawlspace, the key will be gone.
- Unlocking the door to get to the Mausoleum version of Mom's Heart consumes the knife familiar.
- It's possible (though useless) to acquire another Knife Piece 2 using Forget Me Now and R Key.
|The Binding of Isaac: Rebirth|
|Achievements||Attributes||Bosses||Cards and Runes||Challenges||Chapters|