Alternate history is a branch of science fiction, where the science in question is history, and for all its linchpin corniness I like it. (Btw I wonder if Robert Silverberg’s 2000 short story A Hero of the Empire, where Muhammed is killed to prevent the rise of Islam, could have been published today – in fact, forget I even mentioned it: look over there instead, my hypothetical Islamist readers, please leave mr Silverberg alone!) In The Separation, Christopher Priest weaves two histories together, one where Britain and Germany signed a peace treaty in 1941, and the other, our own, where they didn’t. A pair of identical twins are central to the story and to the mystery of the histories’ relationship to each other. This twin-theme and much more will be familiar to people who enjoyed The Prestige, another Priest novel, which was made into a wonderful movie. There’s the same sense that you’re only gradually being told what kind of story it is you’re reading. This trick is easier to pull off in short stories, but Priest manages it here, and he does it by changing the ground beneath you gradually, while you’re reading, instead of with a burst of twists at the end. It’s all very elegant and I liked it, (Philip K. Dick was good at this as well, although also extremely weird, which Priest isn’t, (Dick’s later plots generally revolve around drug-abusing schizophrenics, which gets tiresome after ten times or so)). I’ll read more of Priest. (He’s also a funny guy.)