Underground Airlines by Ben Winters is a marvel. It takes place in a United States that did not go through the Civil War, and as a result slavery survives in four southern states. Told through the voice of Victor, a bounty hunter charged with returning runaway slaves, it is so realistic in its evocation of this alternate history you don’t feel you are reading fantasy. Thrilling and disturbing both, it’s one of the must reads of the summer. How much humanity Victor will be able to acknowledge and act on is the moral quandary he has to face.