In Derby, Nick needs urgent back-up as a reckless driver tries to avoid capture by ramming his police car, while Alex races to back up colleague John in dealing with an erratic driver who turns out to be carrying a knife.

An insight into the working life of officers patrolling the nation's roads, using modern technology and old-fashioned methods to bring criminals to justice. The officers' hunt for a stolen car ends in a dramatic foot chase, while two reckless car thieves lead them on one of the longest pursuits in the history of the force.