This is a retelling of Edgar Allen Poe’s The Fall of the House of Usher. Set in the kingdom of Ruritani, Alex Easton, recently retired soldier, rushes to the home of the Ushers where Madeine Usher is dying, and her brother Roderick is unable to find a cure. In fact, he’s almost at death’s door himself. Maddy has strange episodes and sleepwalks. Alex feels that the house itself is partly to blame for the Ushers’ conditions. Aided by an eccentric British mycologist and a puzzled American doctor, Alex finally finds an answer to the question posed by the title. I suppose this is on the borderline of dark fantasy and horror, but though I don’t tend to like horror, I love T Kingfisher’s writing, and found this fascinating.