Only weeks into their marriage a young couple embark on a six-month period of separation. Tom Cavendish goes to Japan to build lighthouses and his wife Ally, Doctor Moberley-Cavendish, stays and works at the Truro asylum. As Ally plunges into the institutional politics of mental health, Tom navigates the social and professional nuances of late 19th century Japan. With her unique blend of emotional insight and intellectual profundity, Sarah Moss builds a novel in two parts from Falmouth to Tokyo, two maps of absence; from Manchester to Kyoto, two distinct but conjoined portraits of loneliness and determination.