A possessed exorcist is forced into a dangerous alliance with a mysterious priest in order to defeat her own father and his army of demons.

Maria enlists Bledsoe's help to destroy a demon and free David from jail. Grace adjusts to life after possession, and Abigail grows stronger.

Maria becomes the target of an obsessive stalker after Abigail leads him on. David falls in with a dangerous group from Bledsoe's past.

Tensions rise as the Society of Sons targets David and Grace; Maria faces a mad demon that Abigail is helpless against; Bledsoe's past comes back to haunt him; and Grace discovers a mysterious power.

A demonic lover makes Abigail an indecent proposal as Maria and Dusty grow closer; and the Reverend forbids his daughter from seeing David. Meanwhile, Grace searches for the truth about her mother.

In order to rescue Grace, Maria must trespass into Purgatory and face a ghost from her own past; and Enos' dark forces draw closer. Meanwhile, David confronts a terrible secret.

Enos pits Maria and David against each other as the ultimate showdown pulls them back to where the nightmare began; Abigail makes a dangerous deal; and the Reverend fights for Grace's life.