Halstead’s past resurfaces when a former Army colleague is implicated in a deadly blast.

As the FBI launches an investigation into Roy’s disappearance, Upton feels the pressure of the secret she and Voight are sharing.

Air Date: Wednesday, Oct. 6 (10:00PM – 11:00PM) on NBC.

NUP_194984_0298.JPG

Picture 11 of 13

CHICAGO P.D. -- "The One Next to Me" Episode 903 -- Pictured: (l-r) LaRoyce Hawkins as Kevin Atwater, Patrick John Flueger as Adam Ruzek -- (Photo by: Lori Allen/NBC)