The book explores the 'underside' of human nature.
the 'underside' of the table
Hollywood's dark 'underside'
(..) I say different! You need to know what you're up against! You need to be prepared. You need to find another place to put your chewing gum... ...besides the underside of your desk, Mr. Finnigan! No way. The old codger can see out the back of his head. And hear across classrooms! (..)2005 Harry Potter and the Goblet of Fire