Strange Key

Strange Key is a trinket added in The Binding of Isaac: Repentance.

Effects

 * Unlocks the passageway to, regardless of run duration.
 * Unlocks, giving it a new effect.
 * The normal effect of Pandora's Box for that level is ignored, and instead 6 items from random pools are spawned.
 * Both the box and the trinket are consumed.
 * If playing with modal characters such as Tainted Lazarus, the character with the Strange Key must enter the room while holding it to cause the passage to open, this may be done re-entering the chapter 4 boss room.

Trivia

 * Strange Key is likely a reference to the film by David Lynch, Mulholland Drive (2001), where a small blue box being unlocked by a strange key is a major plot point.