A British minister is killed by the IRA, in the middle of London, on his doorstep, right under the eyes of his wife and children.  The utter humiliation for the British government, and there is a demand for a quick finding of the assassin.  But that is easier said than done, given the circumstances in Northern Ireland.
Harry is carefully picked and trained.  He is aware his accent is not perfect, but together with a good story it should do.  And he has but one task: track down the killer before he is tracked down himself.

We follow both Harry's slow progress in the field, and the politics and cover-ups behind his back, in London.  Harry really has to set his own personality aside, and overcome his fears - that too is easier said than done.  There are a lot of people throughout the story, but only a few main characters (Harry, the assassin, his wife, and a girl Harry met).  These are carefully painted, and (as far as I can tell...) very accurate.  One can almost understand the hatred, the anger and the violence of the people living there, even if one is not at all accustomed to the environment like me.

The story is well built up, there is a nice balance between the action, the politics and the almost philosophical parts.  The way the story is told made me see it as a movie or a TV-series, when I read it - which was before the BBC made a mini-series based on this book - with longer and shorter shots, wider overviews and close-ups.

Anyway.  I read this a long time ago, in Dutch, and re-read it recently in English.  And to me it hasn't lost it's freshness at all, I enjoyed it again.