Time's convert (2018)

"From the #1 New York Times bestselling author of A Discovery of Witches, a novel about what it takes to become a vampire. Set in contemporary Paris and London, and the American colonies during the upheaval and unrest that exploded into the Revolutionary War, a sweeping story that braids together the past and present. On the battlefields of the American Revolution, Matthew de Clermont meets Marcus MacNeil, a young surgeon from Massachusetts, during a moment of political awakening when it seems that the world is on the brink of a brighter future. When Matthew offers him a chance at immortality and a new life, free from the restraints of his puritanical upbringing, Marcus seizes the opportunity to become a vampire. But his transformation is not an easy one and the ancient traditions and responsibilities of the de Clermont family clash with Marcus's deeply-held beliefs in liberty, equality, and brotherhood. Fast forward to contemporary London, where Marcus has fallen for Phoebe Taylor, a young employee at Sotheby's. She decides to become a vampire, too, and though the process at first seems uncomplicated, the couple discovers that the challenges facing a human who wishes to be a vampire are no less formidable in the modern world than they were in the 18th century. The shadows that Marcus believed he'd escaped centuries ago may return to haunt them both--forever. A passionate love story and a fascinating exploration of the power of tradition and the possibilities for change, Time's Convert will delight fans of the All Souls trilogy and all readers of magic, the supernatural, and romance"--