The PCs come to a room full of doors. One announces that: "One of us tells the truth, another always lies. A third is a gossip, while a fourth door just cries. Other doors don't talk at all, as they're just too shy. Our creator has a talking door fetish, please just help us die."
The PCs are all impaled when they fail to realize that the door that told them, "One of us tells the truth while the other always lies" was lying about the entire setup, as both doors led to spiked pit traps.