Another moment from Treehouse of Horror XXV, from a different segment this time. Remember Time and Punishment, from Treehouse of Horror V? That's the segment where Groundskeeper Willie shows up in an alternate universe to help Homer, only to have Maggie kill him with an axe to the back, stating "This is indeed a disturbing universe" after she does the deed. Well, Willie didn't forget. And twenty years later, Willie got his revenge in The Others, where the modern day Simpsons meet their Tracey Ullman selves, and everyone winds up being killed off. At the end, the Simpson kids realize Maggie has been killed off too, and Lisa ponders "Wait, who killed Maggie?" The scene then cuts to Willie (who is dragging off the bodies to make stew) looking shifty-eyed.