Lt. Severide teams up with Seager and the OFI when a motel structure fire turns suspicious. Firehouse 51 members become amateur sleuths following a Reddit post involving one of their…

The death of a sailor repairing the ships radar dish leads Mac to prosecute and Harm to defend the sailor charged with the death. At the Naval Academy, Mikey’s friendship…

The investigation into the death of a pregnant teenager exposes a long-held family secret which precipitates another violent death and the destruction of two families.

Speedle and Delko are present when a trendy nightclub catches fire, apparently from a DJ’s pyrotechnics display, killing sixteen people and injuring dozens of others. But the ensuing investigation reveals…