First appeared in Nightmare.
The narrator couple try to keep a beast outside their house. They build and build--including a safe room--until they've sealed themselves inside. Once inside they're not sure what to do until they're not sure what to do since they've been building so long. However, they realize that they've built the beast inside. Into the safe room. All that's left, they initially think, is a ritual. But once performed, could they have come up with another choice? Th climax is gruesome.