When a tanker bursts open east of Toronto, a young operator faces a toxic mess; Gary reacts fast when he spots a dangerous mistake on the road; a rookie takes the controls for his first heavy job.

A pileup on the 401 brings traffic to a standstill and pushes the Ross crew into action; Sonny helps a driver stuck on a dangerous stretch of highway in Toronto; Herb's rookie Zach masters a difficult move for the first time.