Annika Boras

The detectives go under cover to arrest a man who brutally attacks other men; a deceptively tough defense attorney (Nia Vardalos) complicates ADA Barba's case.

The search for the serial arsonist leads Severide to meet face-to-face with an old enemy.

The Machine issues the number of a prominent New York lawyer whose husband was recently murdered, and the team has to quickly determine whether she orchestrated the death, or if she is being framed. Meanwhile, Carter faces an issue with her new partner, Mike Laskey, after he spots her with Reese aka "The Man in the Suit."

Surprising evidence is uncovered that sheds new light on the fire that killed Shay.

The pursuit of a missing teenager leaves Mills and Brett stranded in unforgiving elements; members of the firehouse care for an abandoned newborn; Severide receives an intriguing proposal; Boden is at odds with his father (Richard Roundtree).

Betty tries to make amends when Gio returns; Daniel receives some shocking family news.