This is a “companion piece” to Atkinson’s completely wonderful Life After Life. There was no way she could possibly top that.
Our protagonist of Life After Life, Ursula, lived many possibly lives in the novel, and this is the story of one of her brothers, Teddy. Atkinson has kind of assumed one of Ursula’s realities, since she features a little in the book, but this is mostly about Teddy’s war, and subsequent years, and his offspring.
This is sorta-kinda in the same vein as Life After Life in that it skips about in time to tell the story, and we hear from several of the characters’ perspectives in order to tell it properly. Such a lot of this book is about Teddy’s offspring, and of course every human is created by chance, and might not have existed but for the smallest change in choice of actions, just as every one of Ursula’s realities changed course from the smallest of changes.
This is a nice enough novel and certainly thought-provoking with an excellent and sobering ending.