Who could possibly take on such a maverick terrorist?

Well that has to be the forces of law and order. The agencies we have set up to pursue those who operate outside the law - the terrorist. Spurred on by a killing that is claimed by the IRA, they all become involved in the hunt. And where there is more than one hunter there are bound to be antagonisms, competition and diversions.
And so we have a mix of deceits, lies, outright confrontation and violence as the hunt for a terrorist unfolds in the very heart of London. Meanwhile the politicians look to offer the public at large a smooth and comforting picture of events.