S4, E11: A tornado threatens the city and Herrmann (David Eigenberg) discovers the path may hit close to home. Chili (Dora Madison) and Brett (Kara Killmer) lock heads when Chili makes a critical mistake that leaves a victim breathless, prompting Brett to report to Chief Boden (Eamonn Walker) regarding Chili's erratic behavior. Meanwhile, Otis (Yuri Sardarov) pleads for Dawson (Monica Raymund) to help him solve his women troubles, and Severide (Taylor Kinney) is asked to lend assistance to agent Alex Ward (guest star Liza Bennett) from the Department of Homeland Security regarding a suspicious home.