A chance encounter at a concert has a mortal woman, Cara, meeting an immortal Spirit. It doesn't take long for passion to flare between them.
But her new friend has some secrets of his own.
A rogue Spirit is killing mortals, and the Spirits of London must deal with it or risk their existence becoming public knowledge.
When Cara is placed in danger because of her friendship, the Spirits of London must attempt a rescue - and in doing so they learn all is not as it seems with the rogue.