In War Times

Built around the wartime diaries of her own father, an engineer in the American occupation force in Germany in 1945, for much of its length this reads like an exceptionally good historical novel. But slowly we become aware of strangeness creeping in: a mysterious European physicist leaves our hero, Sam Dance, with plans for a device that, it is claimed, will end war. But though Sam keeps tinkering with it, he can't make it work. Eventually, however, we realise that the device has opened up other time streams, and when Sam's daughter realises it can be used as a time machine she heads back to 1963 to prevent the assassination of President Kennedy. Why it's on the list: In War Times won the John W. Campbell Memorial Award, and with its sequel, This Shared Life (2011) it presents a vision of multiple histories that builds its sense of menace slowly and very effectively. The result is a work of science fiction that ends up being extravagant in its invention, yet which is very solidly and convincingly built upon a foundation of our own history.