We follow three families – the Wellwoods, the Cains and the Fludds – who are all living in, or drawn to, the Kent marshes, from the latter decades of the nineteenth century to the early part of the twentieth. The stories of children’s author Olive Wellwood (loosely based on E. Nesbit) provide the early spur of the tale. But for nearly 600 pages of The Children’s Book there is a big problem: A.S. Byatt’s Possession saw two academics engaged on a quest to uncover a literary mystery, a clear line of plot movement from beginning to end. There is no such momentum here. We get a lot of Kent topography, a smattering of European folklore. More about the genesis of the Victoria and Albert Museum than anyone outside a course on the subject could possibly need. A mass of pottery. And endless bloody puppet shows. But no narrative drive. The book is not actually heading towards anything. It just is. This happened, then that happened – the Fabians and the anarchists, the unequal struggle for women’s suffrage, the machinations of the European powers, Asquith this, HG Wells that. The book is full of adults who believe they are free thinkers and should know better. Much is made of changelings and cuckoos in nests: there are family secrets, a tragedy or two. What saves it all is the tone – A.S. Byatt’s asides, rationed out every few pages, are deep-frozen, skewering her characters’ pretensions in one or two limpid sentences. In the final 40 pages of the book it becomes apparent that we have, in fact, been hurtling towards something – that something being the First World War. No-one – particularly the many male protagonists – ends up well. All of the children – by now young men – are either killed or maimed or have some other cause to regret the cataclysm. And here, again, Byatt’s detachment serves the story well. The Great War is a gift for any author but you still have to use it wisely. Her dreadfully simple, almost offhand, modes of expression perfectly match the casual, passing horror of the carnage. You are made to wait a long time for something so moving and worthwhile, however. It took all of November to read it.