An ancient Boston catacomb is unearthed, releasing a malevolent spirit that may threaten the Legacy. Father Philip Callaghan returns.

After leaving the Legacy, Kristin plans to help expose the murderous Benjamin Church after the alliance between "Doctor" Benjamin Church and Horton causes Ethan's death.

Nick's former Navy buddy, Mike MacCreedy resurfaces with a strange woman who seems familiar to Nick and exhibits an unnatural interest in him.