So I was changing my bed linen - not an event of note. Only this time, when I got to the point of changing the bottom sheet, the replacement was nowhere to be found. Not accidentally in the laundry with the old bed lining. Not escaped loose in my bedroom. Not sulking, still hiding in the bed linen draw. After searching for several minutes I finally tracked the fugitive down. Somehow it had managed to get inside the duvet cover, and was hiding right down at the furthest point from the seam of poppers. This is a new one on me. I will have to watch that bottom sheet more carefully in future - I wonder when its first escape bid will be.