Selma Rose (Patricia Hearst), the wealthy granddaughter of Hearst College's founder, mysteriously disappears the night before she is to cast a swing vote that will determine the fate of the Greek system on campus.
Boden thinks he's being set up by his neighbor; Severide's father pays him an unexpected visit; romance is in the air at the Chicago Fire Department gala.
Nate and Brenda find comfort; Ruth has a surprising self-assessment; Federico becomes suspicious of Vanessa; a former client sues.
Lane's band makes its debut at a big bash, where Jess and Dean's long-standing animosity erupts into a brawl.