S3, E7: Members of Firehouse 51 are forced to contend with a house fire, but when the injured owner is rescued from his cellar clutching a suspicious box, Lt. Severide (Taylor Kinney) brings in Sergeant Voight (guest star Jason Beghe, Chicago P.D.) and Detective Lindsay (guest star Sophia Bush, Chicago P.D.) into the mix for further investigating. Elsewhere, Mills (Charlie Barnett) wonders if the dangers of Newhouses’s (guest star Edwin Hodge) off-duty gig are worth the cash returns, while Molly’s II is in dire need of a good chef.