The door itself is a targeted rift, not dissimilar to the natural rifts leading to [[The Raving In-betweens]]. Due to collecting [[Inter-reality Dust]], the entity generating the rift is able to project the rift as a physical construct, in this case appearing as a closet door.
When encountered by [[The New Exodus Vanguard]], it was identified that [[ClintAlvarez]] had previously encountered the entity, as he tried to sacrifice [[Cheng Yao]] to satiate it for another six hours. It is strongly implied that [[ClintAlvarez]] sacrificed his own family to the door in order to avoid being taken himself.
[[Cheng Yao]] successfully disabled or destroyed the door through use of a suitcase nuclear device, which detonated deep within the rift itself. It is presumed that the explosion has destroyed or seriously damaged the organism generating the rift, as it has not subsequently reappeared. [[Cheng Yao]] was able to escape the detonation, and survived to rejoin his squad.