The Fortress by Danielle Trussoni

A New York Times bestselling author's marriage memoir is "a page-turner and a profound meditation on the nature of desire and freedom in the modern age" (Cheryl Strayed, New York Times bestselling author of Wild)
"If I had been another woman, I might have been skeptical. But I wasn't another woman. I was a woman ready to be swept away. I was a woman ready for her story to begin."
From their first kiss, twenty-seven-year-old writer Danielle Trussoni is spellbound by a novelist from Bulgaria. The two share a love of jazz and books and travel, passions that intensify their whirlwind romance.
Eight years later, hopeful to renew their marriage, Danielle and her husband move to the south of France, to a picturesque medieval village in the Languedoc. It is here, in a haunted stone fortress built by the Knights Templar, that she comes to understand the dark, subterranean forces that have been following her all along.
Danielle's time in the fortress brings precious wisdom about life and love that she could not have learned otherwise. Ultimately, she finds the strength to overcome her illusions, and start again.