Luther is a darkly humorous mafia book that tells the story of Luther LaMotta, an accidental low-level hitman in the Manchini family mob. Luther wants nothing more from life than to savor music in the solitude of his plant-filled apartment, or to romp in borrowed luxury cars with his girlfriend/stripper Candy Barr, an Amish runaway. Instead, he is forced to clean up after mob hits, feeding victims' body parts to a crocodile named Bianca who is kept in a pit in a New York City basement.

Despite the constant violence surrounding him, Luther retains a charming naivete, which makes him an easy target for manipulation. Willing to do anything for Candy, Luther becomes embroiled in her plot to skim money from the Manchinis, and he realizes—only after irreparable damage is done and lives lost—that she has set him up.