Thirty-Three Swoons by Martha Cooley
Years after the end of her marriage and the death of her father - a talented perfumist - Camilla Archer's tightly reined existence is upended by her dreams. A man who seems utterly real begins appearing to her as she sleeps, a mysterious figure in a mask and tuxedo, offering up distorted versions of key moments in her life.
So begins Camilla's piecing together of the puzzle of her family's past. Travelling in memory and reverie back to Moscow and Paris between the wars, Camilla finds that she has been granted the chance to unknot her life-if only she's willing to ask what the ghostly double who has infiltrated her dreams is wanting her to discover.