In Chicago Fire season 3, episode 3, "Just Drive the Truck," a high-stakes rivalry causes a collision between Truck 81 and Truck 66, sparking a legal crisis for Joe Cruz after another firefighter runs a red light. The episode also features Peter Mills transitioning to a paramedic role following a vertigo diagnosis that prevents him from continuing on active rescue duty. Read a full recap of the episode on Chicago Fire Wiki . [S3E3] Just Drive the Truck