Alternate political realities are compellingly explored in this sinister vision of a children’s home – but the echoes of Ishiguro are just too strongIn 2016 Catherine Chidgey published her fourth novel, The Wish Child, a child’s-eye view of Nazi Germany. Since then the much-garlanded New Zealander has contrived to be not only conspicuously prolific but also intriguingly unpredictable. Though she returned to wartime Germany in her Women’s prize-longlisted Holocaust novel, Remote Sympathy, her work has ranged from the coming-of-age psychological thriller Pet to The Beat of the Pendulum, a “found” novel that drew on everything from conversations and social media posts to news bulletins and even satnav instructions to create a picture of one woman’s life over a year. The Axeman’s Carnival, published in the UK last year, was partly narrated by a magpie. Like The Wish Child it won the Acorn prize for fiction, making Chidgey the only writer to win New Zealand’s most prestigious prize twice.The Book of Guilt appears to mark another departure. Chidgey describes her ninth novel as her “first foray into dystopian fiction” and, while the book purports to be set in England in 1979 with a female prime minister newly ensconced in Downing Street, it is not the country we know. In Chidgey’s alternate universe, the second world war ended not in 1945 with allied victory, but in 1943 when the assassination of Hitler by German conspirators led to a swiftly negotiat