Little Mouse can't sleep. He can hear huffing and puffing outside the house. Something is tapping on the window, and there's someone calling Hoo-hoo! Hoo-hoo! out there, too! Little Mouse asks if he can sleep in Big Mouse's bed. But Big Mouse is determined that Little Mouse should sleep in his own bed. Can Big Mouse help Little Mouse with his fears or will they both be up all night long trying to get to sleep?