Ghost in the Mirror — Elizabeth Maxim

FX Expert turned psychic investigator Matt Winters has met the woman of his dreams, in Gold Rush era San Francisco.  Though time travel is right up the paranormal alley, he needs to get back to his own time.  And he's not going alone.  With one hand in the past and another reaching for the future he's determined to have it all.   Consumed by guilt after her colleague falls through her time gate, paranormal investigator Kerry Murphy puts her life on hold to focus all her energy on getting him back to the present.  But life, like time itself, waits for no one and if she doesn't find a way soon, his future and hers will slip from her grasp like sands through an hourglass.