Agyrem, also known as the Ghost Quarter, is a ethereal and insubstantial realm tied to the plane of Ravnica. Very little is known of Agyrems origins or purpose, and what evidence has been gathered is often contradictory and confusing. It appears to be a ghostly version of the city of Ravnica, a land without color or substance, dotted with structures and spires that have long since been torn down and destroyed on the material plane – many believe that Agyrem contains all things that have been lost. It is populated solely by ghosts and restless spirits, who move about the Ghost Quarter without any obvious purpose or intent, seemingly listless. Even the long-dead magic of the Guildpact supposedly holds sway in Agyrem.
Agyrem remained a distant realm until after the events of the Dissension Crisis and the healing of the Schism, when it briefly overlaid itself with the material plane. For a time, the Ghost Quarter and Ravnica occupied the same space, the ghostly inhabitants and beings seen but never felt or heard, the transparent and hazy spires occupying Ravnica’s vast skyline. During that time it was patrolled by a special spectral unit of Azorius and Boros spirits, led Agrus Kos, to protect both mortal and ghost from the rogue phantom of the vampire Szadek. Barely had the people begun to grow accustomed to this change when Agyrem vanished again, becoming its own plane once more. This has generated more curiosity about the nature of the Ghost Quarter, why it exists and what purpose it fulfills or has yet to fulfill.