Stained Glass

Blackford Oakes is sent to Germany to stop a righteous nationalist from starting a world war

When the Wehrmacht took Warsaw, Alex Wintergrin led the charge. But as soon as Hitler’s army occupied the Polish capital, the charismatic young count disappeared, and he was assumed to be dead. But that couldn’t have been further from the truth. Wintergrin had ditched his uniform and turned himself in to Polish security forces, with whom he shared every scrap of Hitler’s plans for the invasion. He then waited out the war in Norway, fighting the Germans with the resistance. Now the fighting may be over, but for Wintergrin, a new battle has just begun.
 
When he starts inciting East Germans to throw off the yoke of Soviet oppression, the USSR threatens to roll its tanks across Europe. In order to keep another war from breaking out, the CIA must send in the charming devil Blackford Oakes to talk sense into Wintergrin—and if necessary, kill him.
 
Stained Glass is the 2nd book in the Blackford Oakes Mysteries, but you may enjoy reading the series in any order.