I knew I was getting close when I came across mouse droppings in with the dust rags. It was hiding in the back corner with the vaccuum tools. I'd forgotten how fast mice are, and how high they can jump. It was a ten-minute task to manage to catch mousie, even in the enclosed space. I finally got it into an old cereal box. Took it out to the back fence and put the box down. Mousie can take it from there.
I think I know the newest mouse refuge. Both Ming and Hobbes are now *very* interested in the tool shed. I suspect this means this is where mousie has ended up. Circe, meanwhile, hasn't given up on the linen closet. It probably still smells like mice, despite my sweeping out all the droppings. I figure she'll be camped in front of it for a few more days.