A prominent Boston family discovers that one of its own may be behind a series of infamous grisly killings as the case of "The Silver Bells Killer" is reopened.

Tragedy strikes the Hawthornes; Cam, Tessa and Alison look for an explanation for the silver bells they found; Garrett plans to expose a family secret; the police inquiry into the "Silver Bells Killer" sends Brady on a hunt for DNA.

Police focus their investigation on the Hawthornes, Cam wants to erase his past while Garrett embraces his, and the behaviour of one of Alison's siblings complicates her campaign.

A death on the Hawthorne property turns into a solid lead for Detective Brady, Garrett gives in to temptation and goes after Christina, and Alison finds an unexpected ally.

Cam experiences hallucinations that make him question his involvement in a gruesome crime, while Madeline leaves town to confront the sender of a cryptic message.

The Hawthornes turn on one another after they are publicly implicated in the SBK case, forcing them to stay at the house to avoid the media. Meanwhile, Garrett takes Christina on a camping trip that takes a dangerous turn.