Karl is called to an accident involving a driver in his seventies who has reversed into a house and ruptured a gas main. With the elderly man trapped in his car, it's a full-scale emergency for Karl and his colleagues to free the driver and prevent an explosion. On the outskirts of Derby, traffic cop Jason is called to a mystery crash involving a middle-aged woman who has rolled her car on a quiet suburban street. Unsure why or how the accident has occurred, Jason is left gobsmacked when the truth is revealed.