As the new year begins, a terrifying evil from across the centuries of Earth's history is stirring. As the Doctor, Ryan, Graham and Yaz return home, will they be able to overcome the threat to planet Earth?
Cole finds himself on the rebound after Natalie's engagement, and his new romantic interest, Julie, has an unexpected connection to A.D.A. Erica, complicating things at work. Meanwhile, Murtaugh worries about the connection between the murder he's investigating and a new opportunity for Trish to serve as co-counsel on a high-profile lawsuit with Leo Getz.