Kind of a Crazy Idea

S4, E21: Dawson (Monica Raymund) makes an attachment to a young boy she rescues in an apartment blaze while Kidd's (guest star Miranda Rae Mayo) big idea for Molly's turns into a disaster. Lt. Severide (Taylor Kinney) makes a pitch for the house to upgrade some of their fire masks but hits a wall in his efforts, prompting Lt. Casey (Jesse Spencer) to use his political influence to pull a few strings. Meanwhile, Cruz (Joe Minoso) and a reluctant Brett (Kara Killmer) bring in a secret weapon in their efforts to get Otis (Yuri Sardarov) to see Dr. Halstead (guest star Nick Gehlfuss) and take a blood test.