The Bear's Tears (1985)
A Russian defector is picked up by the Americans and the news he brings isn't welcome. Kenneth Aubrey, newly promoted to head of MI6 is a double agent and has been working for the East since 1946 when he was captured by the Russians in East Berlin. The defector brings with him photographs of a file called Teardrop which proves it. Aubrey is arrested and fellow spy Babbington is put in charge in his place.
Except it isn't true of course. Patrick Hyde has his doubts and finds himself on the run in Vienna. And not just from the KGB. His own side want him too. A handful of people are finding it hart to believe that Aubrey is a Russian spy and decide to get to the truth. This means Hyde has to make his way first to war-torn Afganistan to confront Petrunin (from Sea Leopard and Jade Tiger) once more. The Russian is the architect of Teardrop and only he can give Hyde the key.
As if that wasn't enough Hyde has to cross the Iron Curtain into Czechoslovakia to get the proof out of the KGB's main computer.
Simply put The Bear's Tears is an excellent thriller. It's Thomas' longest and best book pulling togeather characters from most of his previous novels. They don't get any better than this.
Last of the 'Petrunin Trilogy' and first of the 'Babbington Trilogy'.
On a personal note I remember seeing the paperback displayed in a "dumpbin" in a shop with a cardboard Hind Gunship on top back in 1985!
Illustrator Chris Moore is the artist behind the Hind helicopter image for the original "widescreen" cover of the paperback.