Danny Johnson

An online paedophile ring -- including two high-profile suspects -- is targeted in an undercover sting.

A key witness in Danny's case is killed the day before testifying and Erin asks Anthony to help find the killer, which angers Danny more.

Jamie and Renzulli are injured by a church's security team when they respond to a 911 call, and Frank must deal with the political fallout from the incident.

Alex is training at the CIA and discovers a deadly conspiracy that threatens everyone around the world.

A new captain takes over the GCPD and seems just as determined to clean up the city as Jim Gordon. However, as the new guy begins to ask questions, Gordon begins to worry that his own unsavoury associations might come to light.

Tony runs into some trouble on a business trip to the West Coast. Christopher decides to discuss terrorism with the FBI. Meanwhile, the New Jersey family ends up mourning the loss of another one of their associates.