Sure. It's pretty simple. As you've probably noticed, you're in the City, which is an interdimensional vortex that sucks in people from all manner of universes, et cetera et cetera. Occasionally there are curses, where something insane and possibly intensely horrible happens to a segment of the population for no apparent reason.

For example, today there's mistletoe everywhere and if you're under it, you can't help yourself.