Set in modern-day London, a group of radical activists take over an energy company’s annual event, taking 300 hostages to expose the corruption of their owners. Their righteous cause is hijacked by an extremist within their ranks who is willing to kill everyone in the building to send his anarchic message to the world. It involves a former soldier turned window cleaner, played by Daisy Ridley, who scales the building’s exterior 50 stories above to rescue those trapped inside, including her younger brother.