While working at a sobriety checkpoint, Burgess finds a duffel bag full of heroin in the truck of a respected college professor who claims to know nothing about how the drugs ended up there. At District, Roman expresses his desires to become a Field Training Office to Platt, and Mouse sets Halstead up with an off-duty security job working for the attractive owner of a medical marijuana clinic.

Burgess gives chase after Roman is wounded by a hooded perp who opened fire on their patrol car and shoots who she thinks is the suspect, but no gun is found at the scene—and the person she shot is a 17-year-old honor student.

Intelligence investigates a string of bombings targeting members of the media. Racing against a ticking clock, the team enlists Firehouse 51 to help examine the devices and prevent the next attack.

The crossover continues on Chicago Fire S06E013 Hiding Not Seeking (II).

Using information from Chicago Fire's Cruz, Intelligence chases down the robbery crew that’s been using the lockbox key. Voight is under pressure to bring the crew to justice without tarnishing the reputation of a murdered firefighter who might have been involved.

The crossover starts on Chicago Fire S07E15 What I Saw (I).

Intelligence searches for the dealer who caused multiple overdoses and is connected to Roman's missing sister. The case becomes a homicide investigation when they find the dealer's dead body.

The crossover starts on Chicago Fire S08E15 Off the Grid (I).