Binding of Isaac: Rebirth Wiki

(in Repentance)

Knife Piece 2 is a passive item added in The Binding of Isaac: Repentance.

Effects[ | ]

  • Combines with Collectible Knife Piece 1 iconKnife 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 MausoleumMausoleum/GehennaGehenna II will open the door, destroying the knife in the process.

How to Acquire[ | ]

  • In MinesMines/AshpitAshpit II, if Isaac has Collectible Knife Piece 1 iconKnife Piece 1, 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 ShadowMother's Shadow will pursue Isaac through the corridor. Getting to the end of the area will seal it off.

Notes[ | ]

  • Obtaining Knife Piece 2 without Collectible Knife Piece 1 iconKnife Piece 1 will spawn a knife blade familiar that follows Isaac but has no other effect.
  • The door to the abandoned area can be opened with two explosions or items like Collectible Dad's Key iconDad's Key, however Isaac will not be able to reach the door unless he has flight or all three buttons have been pressed anyway. If the door is already open, the minecart cannot be ridden but the path can be walked along.
  • While in the abandoned area, all of Isaac's items and consumables are removed. Extra Life items will not activate despite still visually appearing beside the health bar. However, any items with reroll protection will still function as normal. (This includes Collectible Knife Piece 1 iconKnife Piece 1 itself.)
  • If a character has inherent flight, they will retain it in the abandoned area, making it significantly easier.
  • 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. Upon exiting the room, the rail pathway will be built in order to prevent softlocks from using temporary flight methods such as Collectible The Bible iconThe Bible.
  • The red door can alternatively be opened using Collectible Cracked Orb iconCracked Orb, Collectible Sharp Key iconSharp Key, or Soul of CainSoul of Cain.
  • If Isaac takes Knife Piece 2 and is somehow able to immediately leave the room before Mother's ShadowMother's Shadow fully activates (usually by using Collectible Mama Mega! iconMama Mega! earlier in the floor), the rest of the sub-area will not have reset, and the doors leading to the exit will all be locked. This forces the player to re-enter the Knife Piece 2 room, which triggers another activation of Mother's ShadowMother's Shadow, causing two instances of Mother's Shadow to pursue the player during the escape sequence.
  • 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.
    • Black market can be entered from the crawlspace. Going through the trapdoor there will end the pursuit and lead to Depths I (or alternatives). Isaac will keep all his items, including those bought in the market.
  • The knife familiar created from both knife pieces takes 5th priority on the line of following familiars.
  • Knife Piece 2 takes 6th priority on the line of following familiars while the knife familiar created from both knife pieces takes 5th priority.
  • It's possible (though useless) to acquire another Knife Piece 2 using Collectible Forget Me Now iconForget Me Now or Collectible R Key iconR Key.
  • Character Tainted Eve iconTainted Eve retains her ability to create clots, but loses access to Collectible Sumptorium iconSumptorium. Caution should be used if entering with low health as clots cannot be reabsorbed until exiting.

In-game Footage[ | ]

Trivia[ | ]

  • Knife Piece 2 is from the Antibirth mod. In Antibirth, Isaac would acquire Knife Piece 2 by pressing the right sequence of buttons in a special room instead of entering the abandoned area and being chased by Mother’s Shadow. Once the sequence was solved Knife Piece 2 would always automatically appear in the center of the special room on subsequent runs.
    • Knife Piece 2 was also not the final piece with 3 knife pieces being needed to be combined to make the knife familiar. Moreover the sprites for Knife Piece 2 was only the left half of the blade with the 3rd knife piece being the right half.