Had to happen eventually.

Since we moved in here we've had too many books for the shelves. So we'd been stacking them on the front of the shelves, in front of the books that were actually shelved properly.
Well, not anymore. That plus the nice thick plush carpet was causing one of the bookcases to twist in an unpleasant-looking fashion.
So now excess books get stacked on the floor.
More space to put more bookcases would be nice...