From the Women's Prize Shortlisted-author of Weather, an electrifying, funny and wise account of a couple falling out of one another's orbit.

'It is the kind of book that you will be quoting over and over to friends who don't quite understand, until they give in and read it too' John Self, Guardian

They used to send each other letters. The return address was always the same: Dept. of Speculation.

They used to be young, brave, and giddy with hopes for their future. They got married, had a child, and skated through all the small calamities of family life. But then, slowly, quietly something changes. As the years rush by, fears creep in and doubts accumulate until finally their life as they know it cracks apart and they find themselves forced to reassess what they have lost, what is left, and what they want now.

Dept. of Speculation navigates the jagged edges of a modern marriage to tell a story that is darkly funny, surprising and wise.

'Funny, and moving, and true... It tells a profound story of love and parenthood while invoking (among others) Keats, Kafka, Einstein, Russian cosmonauts, and advice for the housewife of 1897' Michael Cunningham