Grace and Mercy are very different women, but are both caught up in the war between Germany and France. When Grace is hit by a loose shell, Mercy seizes the chance to escape her past as a fallen woman and convict by assuming Grace's identity and travelling to England.

From the author of The Woman in White: In nineteenth-century England, a man’s hard-earned happiness is threatened by a priest who covets his inheritance . . . Lewis Romayne has just returned to Vange Abbey, his home in England, after a traumatic experience in France that still haunts him. Trying to shake his memories of a fatal duel, Romayne visits London, where he meets and falls in love with his future bride. But he soon finds himself the object of one man’s obsession. Father Benwell, a priest, is determined to convert Romayne to the Catholic faith in order to regain the abbey, the latter man’s home, which once belonged to the church. Benwell will do anything to accomplish his goal—even sabotage Romayne’s new marriage by exposing a hidden scandal. As this riveting drama unfolds, Romayne must finally decide who is truly entitled to his heart, his soul, and his property.

My wife, in her impulsive way, forgot the formalities proper to the occasion, and kissed her sister at parting. At that one little act of sisterly sympathy, the fortitude which the poor creature had preserved all through the evening gave way in an instant. She burst into tears. I felt as fond of her and as sorry for her as my wife. But (unfortunately) I could not take my wife's privilege of kissing her. On our way downstairs, I found the opportunity of saying a cheering word to her husband as he accompanied us to the door. "Before I open this," I remarked, pointing to the portfolio under my arm, "my mind is made up, sir, about one thing. If I wasn't married already, I tell you this -- I should envy you your wife." He pointed to the portfolio in his turn. "Read what I have written there," he said; "and you will understand what those false friends of mine have made me suffer tonight." The next morning my wife and I opened the portfolio, and read the strange story of George Germaine's marriage.