Paris, 1938. Nicholas Morath, former Hungarian cavalry officer, returns home to his young mistress in the 7th arrondissement. He's been in Vienna where, amid the mobs screaming for Hitler, he's done a quiet favour for his uncle, Count Janos Polanyi. Polanyi is a diplomat and, desperate to stop his country's drift into alliance with Nazi Germany, he trades in conspiracy - with SS renegades, Abwehr officers, British spies and NKVD defectors, leading Morath deeper and deeper into danger as Europe edges towards war.