While Teresa and Jarek set the stage for their case against Alderman Gibbons, their effort to clean up Chicago takes an unexpected turn when a deadlocked jury acquits a corrupt city official. Suspicious, the two mount an investigation, only to discover that jury tampering is just the tip of the iceberg.

The case against Alderman Gibbons escalates when Colvin, Wysocki and Evers scramble to locate a star witness. Meanwhile, as Liam rushes to collect more evidence, he is forced to take matters into his own hands.

FBI Special Agent Cuyler returns to see Superintendent Colvin; Jarek deals with family issues that have haunted him for years; and the case against Alderman Gibbons comes to a conclusion.