(Other Press/Other Press)

Early in Simon Mawer’s fine new novel “Tightrope,”Marian Sutro, a young Englishwoman, joins the hush-hush Special Operations Executive during World War II and is sent to France to work undercover with the Resistance. On a mission to Paris she is captured by the Nazis, tortured and sent to the Ravensbruck concentration camp where, miraculously, she survives the war.

Marian is a fictional character, but her story reflects that of numerous women who worked with the SOE in France, many of whom were found out and sent to concentration camps, where they died. Marian’s story in particular resembles that of the real-life Odette Sansom, who survived Ravensbruck to become a national hero and was the subject of the 1950 movie “Odette.”

In Mawer’s story, Marian returns to her parents’ home in Cambridge after the war and confronts the psychic damage that we call post-traumatic stress disorder: “Normality was so long ago that she could barely recall it and certainly couldn’t aspire to recovering it.” Yet recovery does come. As Marian regains her health, her beauty inevitably attracts men. She had arrived in France a virgin but before her capture had brief affairs with two colleagues, in part because death was all too possible and she was unwilling to die without knowing physical love. After the war, she looks to occasional lovers “to bring with them the paltry comfort of physical intimacy but nothing more.”

As the story progresses, Marian proves to be a woman powerfully driven by desire. Thus, walking with a lover, “she felt it again, that shock of lust that she loved and hated — the kick that was like a drug, a surge of delight and liberation sweeping her up to the summit of sensation; and on the other side of the peak, the slope down which she slid into something resembling the shame.”

After her postwar recovery, she is recruited by a government agency that deals in espionage: “So Marian slid, as smooth as an eel, into that shadow world she had known during the war.” Mawer writes with skill and sophistication about the shadowy world of spies, as he does about sex, love and politics.

To Marian and many others, the overriding reality is that the Americans alone have the atomic bomb. Given that they’ve already used it to destroy two Japanese cities, many Brits fear that the Americans might bomb Moscow before the Russians build a bomb of their own. This leads some to think that the West should share the bomb with the Russians, but several scientists who try to do so are treated as traitors.

Marian feels guilty for having saved the life of a scientist who contributed to the creation of the bomb. In time, she falls in love with a handsome Russian spy, a passionate but unwise alliance that will shape the rest of her life. Her world also includes the husband about whom she soon ceases to care and her brother, an atomic scientist who exists in constant danger because he is gay. For Marian, love and espionage are closely entwined: “Spying was so much like adultery, she thought. The secrecy, the deception, the constant betrayal, in heart as much as in action.”

Mawer, a British writer whose novels include the much-admired “The Glass Room” (2009) and “Trapeze” (2012), captures the political passions of a war-torn age. In Marian, he has created a wonderfully complex heroine. If she is sometimes selfish and manipulative, and if her love for the handsome Russian seems irrational, we must ask how often people are rational about love and, beyond that, what lingering damage a year in a Nazi death camp might do to anyone’s judgment.

Reading “Tightrope,” I thought of Graham Greene’s “The Human Factor,” in which he asked why a man might betray his country. “Tightrope” confronts that same question, and as a work of fiction it does not suffer by the comparison. It’s an ambitious, highly accomplished novel.

Anderson regularly reviews mysteries and thrillers for Book World.

tightrope

By Simon Mawer

Other. 500 pp. Paperback; $15.95