Owl is ready for bed. But as soon as he settles in, he hears a strange noise. He'll never get to sleep unless he can figure out what's going on! He looks everywhere—in his cupboard, underneath the floorboards—even in his walls. But while he's busy tearing his house apart, he doesn't notice one tiny, squeaky, mouse-shaped detail. . . . Will Owl ever get a good night's sleep?