Fateful Reunion by Tina Folsom

Vampiress Roxanne thought that, by joining Scanguards as a bodyguard and starting a new life, she could put her painful past to rest. However, old wounds are opened when a new client surfaces, requesting protection for himself and his companion.

Charles, a witch, has never been able to forget Roxanne, though duty had forced him to leave her without explanation twenty-three years earlier. Now he needs her help to save the vampire and witch world from a dangerous force. But saving the world isn’t the only thing on his mind. He wants Roxanne back.