Source: BBC News
On the fifth floor of Scotland Yard in central London, live video feeds are coming in with news of a terror threat.
The 30 people in the room are forced to make decisions that could change lives - which homes do they raid? Who do they stop and search?
But they are not counter-terror officers - in fact, many of them are not even sure they trust the police.
They are 17- to 25-year-olds from around London, nearly all of them Muslim, and they are acting as if they are officers responding to a terror attack as part of Act Now, an exercise run as part of the government's £140m Prevent programme.
It aims to stop young people feeling isolated or having mistrust for authorities - targeting those that the government and the police agree are vulnerable to radicalisation.