North Yorkshire's traffic cops police the largest county in England and Wales - 6,000 miles of some of Britain's most scenic, and most unforgiving, roads. They deal with among the highest number of serious collisions per person in the UK. This episode follows a major investigation in the aftermath of a collision that has left a young motorcyclist critically injured. The key question for the investigating officers is whether the driver who collided with the rider should have seen the biker before the accident occurred. With the tragic news that the rider has died, the driver faces charges of death by careless driving and the possibility of a prison sentence.