I don't know who set up this prank or why -- or even how -- but I do know it's the best thing I've seen all week.
Pedestrians passing through Chicago's Union Station were baffled to see a mysterious door had popped up in the middle of the concourse.
Behind the door was a tiny, thin room, perhaps only big enough for a person. A sign beside the strange portal simply read: “What is behind this door?”
The brave souls who dared open it were blessed with the cheeriest surprise you'd never expect -- see the video up top to discover the door's contents for yourself.