The Folks at Fifty-Eight by Michael Patrick Clark

I have just finished this book, it was ok, but not brilliant.

Gerald Hammond is the exception to the rule; an honourable spy, whose lofty principles have brought him nothing but loneliness and isolation. Catherine Schmidt is the stunning young daughter of an assassinated spymaster, whose murderous quest for vengeance has left her at the mercy of the infamous Head of Soviet State Security.
On a covert operation, in Soviet-occupied Germany, Hammond has no knowledge of the unseen forces that sponsor and oppose his mission. He only knows that he must somehow save her to save himself, but, as ever-more disturbing revelations come to light, begins to wonder which poses the greater threat; the enemy he runs from, or the friend he runs to?
Set against a factual background of government conspiracy, and one of the most audacious espionage coups in history, the Folks at Fifty-Eight is a beautifully-paced tale of seduction, betrayal, blackmail, and murder that blurs the boundaries between fact and fiction.