Saul Stein

Lindsay deals with the consequences of her actions when her mother is suspected of murder. Meanwhile, Lugo gives Voight an ultimatum.

After the body of a young woman is found with multiple gunshot wounds, Intelligence identify links to other deaths and realise they are dealing with a serial killer. Lindsay finally meets her biological father.

Olinsky goes undercover as a hitman for hire after Lindsay is tipped off about a grieving father looking to avenge his daughter's death. When Ruzek returns from his undercover assignment, Voight puts him on patrol duty.