Another very ambitious novel from David Mitchell, and though it mimics the structure of Cloud Atlas, ultimately it lacks the focus that made that novel such a success. 
 It's hard to go into too much detail without spoiling plot developments in the book, but once again Mitchell is working with multiple narrative viewpoints and multiple time periods. Instead of delving into the past or the future, however, he mostly restrains himself to the present era. There is also an odd mix of the mundane and fantastical, sometimes seeming to compete with each other as the main thread of the story. 
 Mitchell's writing will always be a joy to read, and his characters, as usual, feel very fleshed out and intriguing. But certain sections of the novel are much more successful than others, and a lot of plot strands, particularly in the 2nd half of the book, seem to be either abandoned altogether or spring out of thin air. 
 Edit: I should also note that this book contains several "cameos" of characters from Mitchell's other works. I don't think you need to have read those books, because most of the appearances felt distracting and overly cute to me. But it is kind of neat how all of Mitchell's worlds align in ways you might not expect.