It's painted straight onto a church wall, and for about three hundred years nobody could see it — someone stuck an altarpiece in front of the whole thing, and it wasn't uncovered again until the 1800s. The kneeling pair are the couple who paid for it, though no one seems certain who they actually were. The writing under the skeleton, they say, comes out as roughly: I was once what you are, and what I am you will be.