It struck me that The Midnight has a lot in common with Honest John's tavern in Raymond E Feist's Riftwar Cycle fantasy novels. The story goes that one day Honest John found himself in the Hall of Worlds...
...described as a yellow-white path approx 20ft wide with rectangular silver doors spaced apart every 50 feet or so between which is the nothingness of the void. It is said that the Hall of Worlds connects to every world in the universe. 
...anyway, our hero Honest John stumbled off the side of the path but instead of finding the void he found a pocket dimension and did the only sensible thing - open a pub! Through time this pub became acknowledged neutral ground for the various dangerous beings that stalked the Hall - because everyone needs refreshment!
As a further likeness to The Midnight, Honest John found that he could keep adding to the pub so over time it grew and grew, with some beings setting up their own rooms. There are divergences with The Midnight of course... unless being the landlord here makes m15o effectively immortal, or if all sorts of commerce and bartering creep into the capsules!
Still, the whole concept of Honest John's always struck a chord with me - as does The Midnight in its own friendly pocket dimension. Midkemia fandom wiki