London, 1839. Where the cemeteries are full and there is money to be made in death, Bonnie and Crawford lead a life of trickery, surviving off ill-gotten coin and nefarious schemes. But one hot evening, their luck runs out. A man lies in a pool of blood at Bonnie's feet and now she needs to disappear. Crawford secures her a position as lady's maid in a grand house on the Thames, still deep in mourning for its late mistress. As Bonnie comes to understand this family - the eccentric Mr Moncrieff, obsessively drawing mausoleums grand enough for his dead wife, and their peculiar daughter Cissie, scribbling imaginary love letters to herself from the mysterious Lord Duggan - she begins to question what really happened to Mrs Moncrieff and whether her own presence here was planned from the beginning. Because Crawford is watching, and perhaps he is plotting his greatest trick yet.