Thrice The Brinded Cat
Perhaps the original creation of an ancient race, Mors Frigus is a small demiplane accessed from the Prime Material Plane through portal and password.
Kenric and Sasha discovered a portal to Mors Frigus within the burnt chambers of Fetor Abraxius within the Bluecrater Academy. They managed to activate the portal only to alert the entire Academy administration, which instantly teleported to their position in reaction to what they thought was an illegal break-in.
Upon opening the portal, tons of garbage poured forth and into Fetor’s apartment. Amid the wreckage was a large birdcage with a tiefling girl imprisoned within. The tiefling had absolutely no memory but could otherwise communicate in the Common Tongue. Kenric rescued her from the cage and named her Karina.
When the Bluecrater Administration arrived to find Kenric and Sasha in Fetor’s off-limit apartment with an open portal, they were quite cross with the pair. Kenric was then tasked with cleaning up the mess and fully investigating the portal and the demi-plane that lay beyond.
Kenric completed both tasks and discovered the fate of Maximillian Weer in the process.
Mors Frigus has normal time and gravitational properties. It also is magically aligned. Its atmosphere is exceptionally cold with temperatures far below freezing. Those who suffer non-lethal damage from contact with the cold of Mors Frigus also suffer a loss of memory, starting with the shortest term memory first and then slowly degrading memory back in time.
Very little exists on Mors Frigus. A small building a short ways from the prime portal houses what seemed to be a workshop, of sorts. Perhaps it was also used as a place of chromatic dragon worship at one time for the preserved heads of a red and blue dragon hang above an alter within.
Undead humanoids are known to lie under the cold mud of the surface and will attack several rounds after living creatures step upon the world’s surface.
For more details on Mors Frigus, read Kenric’s report to the Academy.