Billy Smith

Erin is overwhelmed with guilt after a man she set free is accused of killing a cop. Also, Frank and Mayor Poole continue their game of political chicken over Frank's reappointment as commissioner, and Danny and Maria investigate a case of a cop who has gone AWOL.

A member of the Firehouse family clings to life and members of the Chicago Med staff discover a highly unusual parallel between cases - a three-part story arc crosses over into "Chicago Fire" and concludes the following night on "Chicago P.D. Following a knife attack, a member of the team lies in peril and their condition takes a sudden turn for the worse, leaving Dr. Connor Rhodes (Colin Donnell) and Dr. Toni Zanetti (guest star Julie Berman) scrambling to race against the clock. Word quickly spreads that some of Connor's fellow doctors feel he should have operated sooner, causing tension at the hospital. Dr. Natalie Manning (Torrey DeVitto) makes preparations for her pregnancy and Nurse April Sexton's (Yaya DaCosta) brother (guest star Roland Buck III) struggles through his first day at the hospital. Meanwhile, members of the Chicago P.D. Intelligence Unit help investigate whether the case of a women clinging to life after Firehouse 51 pulled her out of a burning building is attempted suicide or murder. As the investigation deepens, a surprising parallel to other patients surfaces.

The murder of a rare bookseller brings Jane and Maura into the world of Keltic writings and coded confessions, just as Maura is preparing Jane to meet her new man. Angela's relationship with Cavanaugh changes pace.

Eric Matheson, a man suspected of killing his wife, is brought in for questioning by the Lightman Group. Determined to prove his innocence, he takes drastic measures that put the team's lives in danger.

Brody's efforts to sever ties with Abu Nazir triggers flashbacks to his time as a captive. Meanwhile, the mosque shooting results in a public-relations nightmare for Carrie.