This week, the team races to a major chemical leak endangering the lives of thousands of people, while in Leeds an elderly motorist is run over by his own car and the HART medics fight to free his leg after it becomes trapped around the front wheel. There's a dramatic emergency at an abandoned school after a teenager falls 30ft down the chimney into an underground boiler room, sustaining serious leg injuries. Team leader Emma must comfort his mum – as well as coordinate a tricky rescue.