A psychologist in suburban Cleveland, Dustin is drifting through his forties when he hears the news: His adopted brother, Rusty, is being released from prison. Thirty years ago, Rusty received a life sentence for the massacre of Dustin’s parents, aunt, and uncle. The trial came to epitomize the 1980s hysteria over Satanic cults; despite the lack of physical evidence, the jury believed the outlandish accusations Dustin and his cousin made against Rusty. Now, after DNA analysis has overturned the conviction, Dustin braces for a reckoning.

Meanwhile, one of Dustin’s patients has been plying him with stories of the drowning deaths of a string of drunk college boys. At first Dustin dismisses his patient's suggestions that a serial killer is at work as paranoid thinking, but as the two embark on an amateur investigation, Dustin starts to believe that there’s more to the deaths than coincidence. Soon he becomes obsessed, crossing all professional boundaries—and putting his own family in harm’s way.