Percival Everett's page-turning new detective novel The Trees is at once gruesome and screamingly funny. A racial allegory rooted in southern history, the book features two big-city special detectives with the Mississippi Bureau of Investigation who are sent to investigate a small-town crime. The murders are hideous in detail, the language is rough, there are racial epithets of all kinds, and somehow the politically incendiary humor is real. Everett talks with NPR's Scott Simon about how — and why — he blended these styles.