Beyond Recall - Gerald Seymour

He had been to the limit. Then they sent him further.

Gary - 'Gaz' - Baldwin is a watcher, not a killer. Operating with a special forces unit deep in Syria, he is to sit in a hide, observe a village, report back and leave.

But the appalling atrocity he witnesses will change his life forever.

Before long, he is living as a handyman on the Orkney islands, far from Syria, far from the army, not far enough from the memories that have all but destroyed him.

'Knacker' is one of the last old-school operators at the modern MI6 fortress on the Thames. He presides over the Round Table, a little group who meet in a pub and yearn for simpler, less bureaucratic times.

When news reaches Knacker that the Russian officer responsible for the Syrian incident may be in Murmansk, northern Russia, he sets in motion a plan to kill him. It will involve a sleeper cell, a marksman and other resources - all unlikely to be sanctioned by the MI6 top brass, so it must be done off the books.

But first, he will need a sure identification. And for that, he needs a watcher...

Full of surprise, suspense and betrayal, Beyond Recall is a searching novel of moral complexity and a story of desperate survival.

Goodreads: 4.01