PC Brian Camsell blue lights to an emergency. As he gets behind a car he hopes will get out of his way, the driver suddenly takes off - sparking a dangerous high-speed chase through Newcastle city centre. And in rural Northumberland, Sergeant Dave Roberts races to a serious crash between a car and a cyclist which is so severe that the car has flipped onto its roof and the injured cyclist is being treated by paramedics. It's Dave's job to work out what's happened and who's at fault