The Many Deaths of the Firefly Brothers by Thomas Mullen

During the depression, two brothers are robbing banks to make a living. James and Whit Fireson, known as the Firefly Brothers to the world, are at the top of their game until they die by being shot... and then come back to life. Without a memory of how they died or where their money is, James and Whit begin their journey to find their lovers, money, and the answers that they so desperately need, but not before they die and mysteriously revive again and again...