After tragedy strikes the Hawthorne family, Cam, Tessa and Alison seek an explanation for the silver bells they found in the shed, while Garrett plans an explosive public announcement about a family secret. Also, the police investigation into the "Silver Bells Killer" sends Brady on a macabre quest for DNA, and a shocking new suspect emerges.
As police begin to focus on the Hawthorne family’s possible connection to the “Silver Bells Killer,” Cam attempts to erase his past while Garrett reconnects with his. Also, Alison’s campaign seeks the support of local professional football player Stephen Gostkowski, but the endorsement is complicated by the risky actions of one of her siblings,
A death on the Hawthorne property gives Detective Brady a solid lead on the "Silver Bells Killer" ("SBK") case. Also, Garrett gives in to temptation and pursues Christina Morales (Catalina Sandino Moreno), the daughter of the first "SBK" victim, and Alison finds an unlikely ally to help fend off a lawsuit that could derail her campaign.
A major revelation about the Silver Bells murders turns everyone’s world in the Hawthorne family upside-down: Christina loses trust in Garrett, Alison’s mayoral campaign sinks, Cam’s sobriety is tested, and Tessa witnesses disturbing new behavior in Jack. Also, Brady is worried that the new information about Silver Bells isn’t exactly what it seems to be.
With a killer taunting them, the Hawthornes look to the police for assistance, but Brady needs Garrett’s help to solve the case. Alison prepares for the election and is rocked by a shocking discovery about her family and the unexpected return of an old friend. Also, as the family gathers for Election Day, they attempt to identify the killer in their midst, but one of them won’t make it out alive.