Ding-Dong Ditch at the House of Doors

A story of the Weird that I'll begrudgingly classify as fanfic. It doesn't take place in, involve the characters of, or even interact directly with the world of Charlie Stross' "The Laundry Files," but I was so fascinated by his series' take on the supernatural that I wanted to ask a simple question: What would happen if the terrifying rules of that world risked bleeding into the Weird's very different, much more amorphous and relatively mellow metaphysics. And so we see Alex Norton (Paranormal Technical Support) at the strange nexus that is the Met Cloisters, facing a door that really, really shouldn't be there.