S2, E4: Two teenage girls have gone missing and the team know the clock is ticking to find them. Halstead (Jesse Lee Soffer), Antonio (Jon Seda) and Lindsay (Sophia Bush) investigate a tenement which gives them a much needed lead. Voight (Jason Beghe) brings the father of one of the girls to district in order to get some honest answers. Meanwhile, Platt (Amy Morton) puts Roman (Brian Geraghty) and Burgess (Marina Squerciati) on gun buy-back duty where they ask questions when they aren’t supposed to. Patrick Flueger, Elias Koteas and LaRoyce Hawkins also star. Charlie Barnett, Stella Maeve and Michael James Reed guest star.