Thirty Balloons (S01E05)

Atwater and Burgess receive a shiny new patrol vehicle, but they struggle to maintain its pristine condition. Their encounter with a deranged woman uncovers a drug trafficking ring that endangers the lives of multiple young girls. Meanwhile, Voight's protective instincts towards Lindsay inadvertently push her into a situation he wishes to avoid, as she aids Justin in staying out of trouble. On a separate stakeout, tension escalates between Olinsky and Ruzek as Olinsky attempts to impart his expertise in the art of surveillance.