Hammer's friend, who was shot and left for dead, seeks the private eye's help in discovering who ordered the hit.
When Hammer and Gleason stop for a drink before their fishing trip, bank robbers hold them and the others in the bar hostage the detectives have left their guns at home.
A vigilante posts a video online of a man, previously locked up for statutory rape, being beaten and burned alive Lindsay encounters some personal and professional problems.
Intelligence investigates armed bank robberies, which point to some surprising suspects Lindsay is forced to make a decision in the heat of the moment.
The murder weapon in the killing of a teenage boy is linked to a case Voight worked on 17 years ago the victim's father wants Area Central Homicide to take the case.
The team investigates a home explosion that left a charred body, one injured survivor and no witnesses Lindsay and Halstead receive a strange warning about Rixton.
When the crushed body of a young teen who ran away from a treatment center for troubled girls is found in an abandoned building, Voight sends Halstead under cover as a guard to investigate the center from the inside.
A priest and parishioners block law enforcement from entering a church where two murder suspects are suspected of hiding Rixton is caught in a lie with Voight.
The investigation into the murder of a sex offender leads to a private police force operating independently of the Chicago PD Halstead checks Jimmy's DNA to find out if he really is Lindsay's father.
Evidence from the case of a young woman who was shot to death confirms the Chicago P.D. has a serial killer on its hands Voight welcomes Kenny Rixton to the team when Ruzek takes another assignment.
Severide is brought in for questioning after it is discovered that his car has been involved in a deadly crash Lindsay considers meeting her estranged father.
A highly trained killer is believed to be targeting the police department Lindsay speaks to Antonio about his job with the state's attorney.
Bull and J.P. Nunnelly clash over their client, a computer cloud company that is battling the FBI to retain privacy over its client files, on the first of three cases to repay her for defending his brother, Benny at trial.
Sue and her unit are assigned to protect a visiting dignitary targeted for assassination by terrorists.
Sue's first assignment involves an anonymous bomb threat at a local oil company Lucy wants Sue to become her roommate.
A deaf woman's ability to read lips gets her a job on the FBI surveillance team.
The team tries to verify the identity of Joe Smith, who claims he served on the U.S.S. Arizona during the attack on Pearl Harbor and wants to be buried there upon his death.
Gibbs and the team assist Ziva with "the one thing" she said she would need to take care of before returning to see her family.
The team's holiday plans are put on hold when a murder investigation leads to the discovery of a newborn baby who has no identification and no apparent ties to a family.
When Kasie and Jimmy are held hostage in a diner after a jewelry store robbery goes awry, they attempt to keep the other customers safe from the thieves.