Sylvia Day takes us into a shadowy underworld, where a powerful angel breaks all the rules by falling for the mortal whose life shes saved...Chained in the dark, Trevor Descansos endures pain and terror as vampires slowly drain the life from him. He finds mercy in Sentinel Siobhán, a beautiful avenging angel with lethal wings. She draws Trevor from the depths of hell, wrapping him in the softness of the same feathers that she wielded like blades to cut down his tormentors.Ageless and eternal, Siobhán has seen too much to be surprised by anything, but the mortal she finds in the pit of a vampire den shakes her to the core. Broken and near death, his ravaged masculine beauty stirs the heart she hadnt realized she possessed. Though shes tasked with eradicating the vampire disease sweeping across her world, she nurses Trevor back to health, healing him even as he awakens a forbidden longing.