Showing Dark Gold by Christine Feehan

Alexandria Houton will sacrifice anything to protect her little brother. But when they both encounter an unspeakable evil in the swirling San Francisco mists, Alex can only pray for their deliverance...And out of the darkness swoops Aidan Savage, a being more powerful and more mysterious than any other creature of the night. This ageless Carpathian male has saved them both from a hideous fate. But is Aidan truly Alexandria's salvation...or her ultimate betrayer? And if she surrenders to Aidan's savage, unearthly seduction is Alexandria in danger of sacrificing more than her life?