The thriller follows the drone operation which is about to strike a terrorist cell in Nairobi, Kenya. Officials are faced with moral questions as an innocent civilian enters the area where the missile is expected to strike. Military officials in different parts of the world watch video of the target area provided by a tiny spy drone. They observe as a Briton-led group of terrorists prepares for a major suicide attack in Nairobi. The officials consider moving from their capture-only drone operation to a deadly one. The military and political debate over the decision delays action and that worries Helen Mirren’s character, Colonel Katherine Powell. She is the leader of the joint military operation. Time is running out. The situation becomes even more complex after a child enters the drone target area. Colonel Powell watches from London. She is ready to kill the terrorists. Her goal, as she sees it is to prevent a possible terrorist massacre.