Erik Hellman

When District 21 goes after a Colombian drug gang following a series of brutal slayings, an asset in the investigation emerges.

Severide feels compelled to help a man he saved from a car accident; Casey and Boden struggle to deal with the orders from Jones' father; a call to duty affects the firehouse.

A large explosion sends Chicago into chaos; the members of the firehouse are tested when one of their own goes missing in the blast.

Antonio believes a Colombian gang is involved in his son's kidnapping; Halstead learns new information about Lindsay; Voight offers Antonio a new way to get information about Diego's whereabouts.

As Voight and his team search for the bombers, they realize there might be more bombs set to detonate; Burgess' niece fights for her life.

When a bartender takes a bullet intended for Halstead, the bounty on him becomes more real; following a tense interaction, Platt and Nadia reach an understanding.