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.