AHaving survived the bomb attack on himself and his family, Voight (Jason Beghe) is out for revenge - and has only one suspect in mind: James Beckett, now freed from prison after Bunny (Markie Post) called into question the testimony Voight gave that put Beckett away.
The team busts Beckett, but he produces an alibi... and makes a new accusation of his own. It seems that 15 years ago, when Voight's team captured him, a million dollars from Beckett's stash went missing. The fingers point initially at Olinsky (Elias Koteas) as the culprit - until an old wiretap resurfaces that clearly implicates one of Beckett's former partners. In an attempt to cover his tracks and keep Beckett in the dark, the partner helped carry out the car bomb attacks. Using the partner as bait, the team is able to capture Beckett.
After his wife issues an ultimatum concerning their future, Olinsky takes a paternity test to determine if he is Michelle's father.