Hellboy and a rookie BPRD agent get stranded in 1950s rural Appalachia. There, they discover a small community haunted by witches, led by a local devil with a troubling connection to Hellboy's past: the Crooked Man.

A dark autumn night. A provincial train has stopped in the middle of nowhere due to a technical failure. On board, everyone is as though competing in shouting for no good reason, apart from one silent man in his thirties, who is totally oblivious to the cacophony around him. When a special news bulletin appears on the screens in the carriage, and the unstable equilibrium between the passengers finally collapses, it is time for everyone to play their separate roles.