The Duke is Back. Lords in Disguise, #6

Everyone thinks he's dead, but the Duke of Harlowe is back in London, ready to avenge his brother's death and reclaim the woman he loved. Miss Sophie Payton never stopped loving Phillip Grayson, even after news came that he died a hero on the battlefield. Now, engaged to his cousin-the new Duke of Harlowe-Sophie's resigned to a loveless match.until the man she mourned walks through the ballroom door very much alive.
Phillip has spent a year in secret recovery, haunted by war, betrayal, and the loss of everything he held dear. When he returns to London, he finds his brother murdered, his cousin wearing his title, and the only woman he ever loved promised to another. But Phillip didn't come back just to reclaim his name-he came to uncover the truth, bring down a killer, and win back Sophie at any cost. With danger lurking and passion reigniting, Sophie and Phillip must decide whether love can survive secrets, scandal.
and a second chance that may be their last. Perfect for fans of Kerrigan Byrne's intensity and Sarah MacLean's heart, The Duke is Back is a sizzling, emotional second-chance romance with revenge, redemption, and a duke who refuses to stay dead.