Arrest in Transit

S3 E9: When the team responds to a semi-truck leaking hydrochloric acid in a busy intersection, Casey (Jesse Spencer) and Dawson (Monica Raymund) find their relationship being put to the test. Meanwhile, Severide (Taylor Kinney) learns more about Brittany’s (guest star Serinda Swan) past and Mouch (Christian Stolte) has some difficulties in his dating life.