Ernest is a poor bear down on his luck (and money. And food) and Celestine is a dentist-apprentice/page mouse who doesn’t really like her job all that much and doesn’t care that Bears are supposed to eat Mice and that Mice should be scared of Bears. Once caught by Ernest the hungry bear, she lays out her case for why he shouldn’t be eating her, and – wouldn’t you know it? Ernest puts her down. They become friends. Then they get into trouble rummaging for food and bear teeth (baby bear teeth are used by dentist mice to give rodents a new set of teeth when their own pair gets worn down). Which gets them into trouble with their respective societies, who behave in startlingly similar ways: vociferous rejection of even the consideration of the possibility that a Mouse (because they weren’t really considering Celestine, per se) and a Bear (because they weren’t really considering Ernest personally either, really) could be friends.