England 1792: every man and woman is bonded to an Umbra – a shadow self that inhabits the unknowable Other Realm. It’s a mortal bond, if either dies, they both do.
Arthur has summoned his Umbra, Amorrie, to attend a ball but she materialises naked, with a broken leg and covered in another’s blood. The ball is disrupted by news of the death of a Countess after her warrior Umbra was murdered in Amorrie’s world.
Among the ballrooms, salons and coffee-houses talk is all of war with France but Pitt’s Government doesn’t yet know that a 500-year-old treaty with the Other Realm is coming to an end, that shadowy adversaries are maneuvering between the realms, that the future of two worlds may rest on an unknown girl who should be human but could be Umbra.