Pcs Emma Keane and Sally Armstrong are out on patrol when London is rocked by two explosions. With the number of casualties rising, Sergeant Stone leads the clear-up operation while Sally, Emma and Pc Will Fletcher attempt to calm the growing hysteria as members of the public try to understand what has happened.
As if dealing with a city in the grip of panic wasn’t enough, Emma and Stone soon realise that a man has been posing as a doctor in order to molest injured women. As Stone catches up with the man, grabbing him by the throat, Emma yells at him to stop. Opposed to Stone’s methods of policing, Emma decides to leave him to it.
On her way back to Sun Hill, Emma notices a building on fire and calls Jack who informs her that another bomb is due to go off. Refusing to wait for back-up, Emma rushes in determined to save lives. Stone begins to suspect that Emma could be in trouble and races towards the building – just at it comes crashing down in front of him.
When Stone finally enters the crumbling building, he frantically attempts CPR as a tearful Sally holds Emma’s hand…