Sweet Tooth?By Ian McEwan,?Jonathan Cape, ?336 pages, £18.99? Ian McEwan writes good beginnings. There is the hot-air balloon in “Enduring Love” (1997), and the grief-racked father looking for his missing daughter in “The Child in Time” (1987). McEwan’s last book, “Solar” (2010), also gets off to a rollicking start when its protagonist, a scientist, finds his fifth wife having a romance with the builder. But with “Sweet Tooth”, McEwan saves the defining moment until the end. The final turn in this thoroughly clever novel fills every hole that has appeared along the way, making reviewing it without giving away the twist rather tricky. Ostensibly, the book is about Serena Frome, daughter of an Anglican bishop, who leaves Cambridge University and goes to work at MI5. It is 1972, five years after the literary magazine “Encounter” was exposed as funded by the CIA, and now the British are starting afresh with a more modest scheme to support writers known to be sympathetic to Western ideals. Serena is given the job of finding a young novelist to back and meets Tom Haley, to whom she gives first money and then herself. “Sweet Tooth” is not really about the secret service or about love. The MI5 bit is fine, but John le Carré did it better. The love bit is fine, too, but both lead characters are oddly stilted (in a way that turns out to make satisfying sense), preventing any wallowing in their mutual happiness.?Instead, this is a sublime novel about novels, about writing them and reading them and the spying that goes on in doing both. As a writer, Tom spies on real life and puts it into his books. As a reader, Serena spies on Tom through his fiction. Equally, McEwan has spied on real life to write “Sweet Tooth”, and in reading it we are invited to spy on him. The clues are thrust in our faces. Tom studied at Sussex University, as did McEwan. Real literary figures casually strut through the pages of this fiction. Tom Maschler at Cape, who discovered McEwan, also discovers Tom Haley. Martin Amis, McEwan’s great friend, reads from his first novel “The Rachel Papers”, and shares a platform with Tom. And the literary editor Ian Hamilton puts away doubles in a Soho pub and dispenses gruff literary advice.?But just as the reader settles comfortably at the keyhole, McEwan teases and punishes by providing too much information — or disinformation. Like McEwan, Tom starts his writing career with short stories, which, although sinister, are not in the same league. While McEwan wrote about chopping up bodies and burying people in cement, Tom writes a relatively wholesome story in which a man falls in love with a shop mannequin, takes her home, is enthralled by her aloofness, but then breaks her into pieces and throws her out in a bin bag. As Tom’s stories are recounted, I found myself as taken with them and as interested in their author as Serena is. Yet the stories suck vivacity from the main narrative — an effect that was probably deliberate. McEwan may well be offering his readers a masterclass in the different crafts of writing short stories and novels. What pleased me most in “Sweet Tooth” was its description of the very British chasm between the arts and the sciences. At first Serena lies to Tom, pretending she read English rather than mathematics at university. Later, when the truth is out, he gets her to recount a probability puzzle, which he doesn’t understand, filling her with “a distinctive and unusual sort of pleasure” for being cleverer than him. Eventually, Tom seems to grasp it, and bustles off to incorporate it into fiction. The resulting story (in which he gets the maths slightly wrong) is in any case dismissed byHamilton, who says he has no time for logical stuff. McEwan is also funny about the way men and women read books. Serena likes Margaret Drabble, A.S. Byatt and Fay Weldon; Tom likes B.S. Johnson, J.G. Ballard and William Gaddis. She likes detail, he likes structure. “Sweet Tooth” has been written to please both of them. It is stuffed with detail: her bedsit is in St Augustine’s Road, measures 3.6x3.6 metres and is furnished with a boxy chair she purchased in a junk shop for £1.20 (Dh7), then paid someone 13 penny plus a two penny tip to carry it upstairs. The novel’s structure is very impessive, with layer upon layer of writers and spies, past and present, and stories inside stories. One needs some sort of map to understand it all, which is only given out at the end of the book. This could be frustrating for some readers. Others may find it a good excuse to go back to the beginning and read this rich and enjoyable novel all over again. From GN