It's about this woman who buys a puzzle in an old junk store. The cover is scratched up so that she can't tell what the picture is, the box is taped shut, and the title is "The Strangest Puzzle in the World". She takes it home to her apartment and lays out all the pieces. As she does so, she notices that some of the pieces have a pattern that resembles her apartment's wallpaper. Nevertheless, she starts to put the edges together. As she works on the puzzle, she can eventually tell that it shows a scene in a room. Specifically, someone sitting at a table in a room.
She stops for a moment, a little afraid, although she doesn't know what of. Telling herself that this fear is silly, she continues to work on the puzzle. When it's completed, she stops dead and stares. It shows her apartment, with her sitting at the table. Only two things are different: the look of pure, blind terror on her face, and a strange face at the window like no human on this earth possesses. Feeling sick to her stomach, she tells herself once again not to be silly, and goes over to the window to prove to herself how ridiculous this is. She pulls up the shade...and sees a horrific face...