I don't really want to try to explain the mechanics of it. But she misjudged the gap between one of the bits that supports the recliner and the open space between it and the seat, tripped, and caught herself on my ankle. With her teeth. It was one of the goofiest things I've ever seen her do. She looked like a total dork.
Once she got her legs extracted from the gap they'd fallen through, she changed her mind about climbing into my lap and is now busy over on the loveseat pretending absolutely nothing ever happened. It was that other cat.
So much for legendary feline grace, eh?