Vanished (Harlequin Nocturne Series #57)

Forever fated to defend humanity against demons, immortal Guardian Rogan Butler has given up all hope of finding peace. But when a beautiful American unexpectedly appears, with all her self-assurance and charm, the winds of danger—and a soul-deep recognition—reawaken the warrior's long-buried desire….

Alison Blair came to Ireland duty-bound to tell Rogan of a sinister premonition, only to be rebuffed. Then evil strikes when her sister mysteriously disappears, and only Rogan can protect Aly from a fate worse than death. Can this brooding warrior be her Destined Mate—the key to a forgotten past, and to her future?