David Orsini's The Ghost Lovers

The past is a dangerous ghostland. 

In David Orsini’s novel The Ghost Lovers, Marc and Simone the protaganists of Orsini's earlier novel, The Woman Who Loved Too Well, are trapped in the ghostland that is their past, even while they continue to fight the Nazis. This time they are searching for a double agent who has caused the deaths of thousands of allies and Resistance fighters. The presence of Hans Mueller—a former Nazi-turned-Resistance ally and Simone’s lover—complicates every aspect of their lives. Marc is determined to win back Simone’s love. He is also determined to prove that Hans Mueller is the notorious double agent.