The Murums

History
The Murums are walls which create and keep the Earth-27 universe. There are four of them In extreme situations walls can be breached and objects from other universes can enter Earth-27.
 * First Wall - Wall of Time which keeps time flowing linearly,
 * Second Wall - Wall of Space which gives boundaries to the realm of the Monitor's creation,
 * Third Wall - Wall of Logic which keeps the other laws of the realm intact,
 * Fourth Wall - Wall of Belief which keeps the Bleed (or "disbelief") from spilling into this realm.

The Murums are protected by the Department of Continuity.

Trivia

 * The Second Wall had a breach on August 10th, 2017.
 * The First Wall had a breach on August 15th, 2017.
 * The beigns which came to Earth-27 from beyond the walls are Elissa Wayne, Fang-Girl, Arkham XX, Trollgirl and Jasonstroke.
 * Some people can look beyond the Fourth Wall and see the Fanatics.