Chicago Fire Season 4 Episode 20 : The Last One for Mom
Detective Holloway (Jenny Mollen) continues to entrust Lt. Severide to watch over her young son at the firehouse while she testifies in court as part of an undercover operation. When the situation takes an unexpected turn, Severide is left to deal with the aftermath. The firehouse responds to a blaze at an art gallery that has a victim trapped inside and prompts Cruz to make a rash decision amid the chaos. Casey receives a suspicious package in the mail that casts suspicion on him from the Board of Ethics. Meanwhile, Brett discovers Otis isn't taking care of his own important issues and confronts him, but finds he is stubborn and more interested in rallying the troops to organize a trip to Las Vegas for the annual firefighting conference.