The Many Deaths of the Firefly Brothers

I just bought: ‘The Many Deaths of the Firefly Brothers: A Novel' by Thomas Mullen. Instead of getting a Kindle edition I got a used hardcover. It was $3.49 with no shipping charge vs. $11 for the Kindle book. In any case, the novel concerns the gangster Firefly brothers. Late one night in August 1934, following a yearlong spree of bank robberies across the Midwest, the Firefly Brothers are forced into a police shootout and die . . . for the first time. Are they inhuman? Are they superheroes? who knows. it sounded fun.