Voight pulls Halstead's badge when Lonnie Rodiger is found dead. After a car accident Severide and Clarke discover the torso of Dr. Elliot who has been instrumental in putting away high profile criminals. With Intelligence down one Sumner is given an opportunity to prove herself. Meanwhile during all the investigation Lindsay and Severide share a moment.

The Intelligence Unit works to find the bombers. Even with government agencies in the mix, Voight and his team work the case from their own angles and connections. Lindsay and Antonio question doctors who handled the transplant surgery for an Ambassador from Syria, but no clues emerge. Olinsky gets some solid intel and the team work from there. It's a race against time as they realize there may be additional bombs targeted to detonate. Meanwhile Burgess sits vigil for her niece whose life hangs in the balance.