John Brock, an archaeologist facing hard times, comes back from a trip to the caves in rural Kentucky, where he failed to find a legendary artifact his family has been pursuing for generations. After his return, he begins experiencing vivid, dream-like visions of a fierce, bird-like creature from ancient myths. John soon realizes that the cave he explored during his last expedition is indeed the one housing the relic, and it also serves as a gateway to Hell and a site for Occult rituals. To put an end to the increasingly lifelike visions, John understands he must return to the cave with his family, locate the relic once and for all, and destroy it.