To protect themselves from the witch hunters, Jake, Cassie and Faye team up to seek out Jake's grandfather, Royce, to find his family's crystal and are confronted with disturbing theories about the events of sixteen years ago. Meanwhile, Diana tries to balance her pursuit of the Glaser crystal with Melissa and Adam with her new romantic life with Grant, who demands to know what she's hiding. At the same time, Callum attempts to re-insert himself into Melissa's life. Also, Charles and Jane plot their move against Blackwell and it is revealed that Diana is the other Blackwell child. Then Blackwell reveals his dark powers are still intact and he wants to use them to create a black magic Circle with his newly found kids.

It's Prom night in Chance Harbor and after Adam uncloaks a crystal hidden in the school, Blackwell tells Cassie she can use her dark magic to find it. When Cassie follows this advice, it leads her to a dangerous discovery. Meanwhile, Faye invites Jake to Prom, despite the fact that he stood her up two years earlier. Adam, Diana, Cassie and Melissa finally make it to Prom but when they lose the crystal to Eben, they end up in a life and death situation. Meanwhile, Dawn attempts to stop Blackwell, who casts a deadly spell on Charles.