S2, E9: A friend of Nadia’s (Guest star Stella Maeve) leads the intelligence unit to a huge heroin bust. Unfortunately this bust results in Olinsky (Elias Koteas) arriving home to find the suspects are holding his wife (guest star Melissa Carlson). Voight (Jason Beghe) and the team think they’ve found a common thread with the suspects but it’s not who they think. Meanwhile Burgess (Marina Squerciati) and Roman (Brian Geraghty) are given an assignment where they get paired with a K-9 officer, Jenn Cassidy (guest star Spencer Grammer) who is Roman’s former partner and girlfriend.