Blade Bound by Chloe Neill

Since the night of her brutal attack and unwilling transformation to vampire, Merit’s stood as Sentinel and protector of Chicago’s Cadogan House. She’s saved the Windy City from the forces of darkness time and again with her liege and lover, Ethan Sullivan, by her side. When the House is infiltrated and Merit is attacked by a vampire seemingly under the sway of dark magic, Merit and Ethan realize the danger is closer than they could have ever imagined. As a malign sorcery spreads throughout the city, Merit must go to war against supernatural powers beyond her comprehension. It’s her last chance to save everything—and everyone—she loves.