On the first anniversary of the Midland, Oklahoma, slaughter, the whole town's looking at Clay like he might be next to go over the edge. Clay wants to forget the past, but the sons and daughters of the Preservation Society ― a group of prominent farmers his dad accused of devil worship --- won't leave him alone. Including Ali, his longtime crush, who suddenly wants to reignite their romance after a year of silence, and hated rival Tyler Neely, who's behaving like they're old friends.

When 17-year-old senator's son Grant Tavish is involved in a fatal accident, all he wants to do is face the consequences. But those consequences never come, even if headlines of "affluenza" do. The truth soon becomes clear: due to his father's connections, Grant is going to get away with murder. When Grant seizes the opportunity to stage an accident on the Appalachian Trail and disappear, the cave system collapses, trapping him miles beneath the surface with four other teens. As they struggle to survive, they realize there's something else down there. And it's hunting them.

Ash may have escaped the cult that killed her mother, but the love of her life is still under its thrall. Dane has been possessed by his ancestor Coronado, a man who's wealthy, dripping with fame and the leader of Europe's most dangerous immortal network. Dane begs Ash to join him at Coronado's castle in Spain, and swears that his blood bond with Ash is stronger than Coronado's hold over him. But when you're all in, blood and salt, the only way to hold on to the light might just be by setting everything on fire.