Pritchard's past comes back to haunt him. 20 years ago, Pritchard covered up a murder committed by a drug lord's girlfriend, who happened to be his confidential informant at the time. Instead of staying on the right side of the law after Pritchard helped her elude the crime, 20 years later she has turned into a major drug dealer (guest star Madchen Amick). So now, Pritchard is determined to set things straight. Meanwhile, Mary's cancer is in remission but she and Otto are at odds over Pritchard, and Otto wants to find a new blood donor for her. Also, Gracie starts dating an older guy.

Pritchard and Duval continue to investigate who Albert Lin really is, who created him and try to uncover how he is involved in a string of murders. The investigation drives a wedge between Mary and Otto, and Otto must choose if he will betray Mary and undo everything they have built, including Pritchard to align himself with Connor Graff. Meanwhile, Gracie goes missing and Pritchard and Duval must race against the clock to rescue her before Pritchard's time runs out.