Alone - The Serenity Series, #1

Meeting a stranger on the worst day of her life changes everything... Caught in a violent and abusive relationship, Serenity thinks there is no escape. But upon meeting a stranger, Sebastian, she is shown the possibility of a different future. Only Sebastian has a dark secret; he is a vampire. As Serenity's life takes a terrifying turn, she finds herself drawn into a world she never knew existed; one of murder, love and immortality.
She is forced to confront her own weaknesses to save both her own life and that of the vampire she has come to love.