THE world in which Sublimation by Isabel J Kim (Picador, £18.99) takes place is much the same as ours, except that when a person migrates they leave a version of themselves behind. One “instance” goes on to the new country, while the other stays at home in their old life. Soyoung and Rose became two people when their mother emigrated to the US. Rose has grown up in New York, while Soyoung — and a version of the mother, of course — remained in Seoul.