Every profiler has an old case that haunts him. For Rossi, it's a sexual sadist who, 30 years ago, the same year the BAU was formed, tortured and brutally killed dozens of young women in a Virginia suburb. When the killings start again, locals believe it's a copycat killing, but Rossi leads our team to discover that this is the work of the original UnSub, who now suffers from Alzheimers. With the help of his son, this heinous criminal has started killing again in order to relive his last murder, which is slowly fading from his memory. Now Rossi must come face to face with his ailing nemesis, mentally break him down and find his son who is moments away from striking again.