Sam and Dean Winchester have spent years hunting demons, ghosts, monsters, and other supernatural threats across America. When a series of unusual cases leads them to the same abandoned town as an independent paranormal investigator, they expect to find another amateur playing hunter. Instead, they discover someone who has been investigating the supernatural alone for years—and who may know more about the case than they do. What begins as a reluctant alliance soon becomes a dangerous partnership as the three uncover a threat none of them has encountered before.