This book blends several genres together seamlessly into one intricate, if not at times wandering, story. There is science fiction, to be sure, but also healthy doses of historical fiction, mystery, and literary fiction in here which make it a good book-club book or crossover novel for those who might ordinarily shy away from more "traditional" sci-fi. I can see it appealing to folks who liked Time Traveller's Wife, or Life After Life.
Harry lives the same life over and over again, much like Bill Murray in Groundhog's Day except the period of time that repeats is his entire lifetime. He makes different choices, learns different things, and has different relationships, but at his core Harry remains fairly consistent throughout his lives. Harry himself, I thought, was relatable if not entirely likable - I found his story interesting, even when he digressed into side stories and minutia (which slows the story down for some folks). His narrative skips from life to life seemingly at random, much in the way we skip from event to event when discussing our own lives. There is a purpose and connecting plot, however, and the central mystery was an interesting one.
The prose is quite adept, and North does a good job of making a complex and clever story readable and easy to follow. There is a fair amount of repetition used effectively in the prose, single repeated phrases standing in for entire emotional events in Harry's past, which act as signposts throughout the story. I never found myself lost, or wondering about motivations even when a character's actions might have otherwise seemed odd. It was well crafted.
The one weak point of the story, and what kept me from falling in love with this book, is the emotional distance. Harry is a bit of a cold fish, and keeps others at arm's length. That distance translated across the board, and left me never truly connecting with Harry, or any of the other characters. I liked the story, writing, and ideas, but as I read a lot for character I never managed to fully invest in this story as much as I would have liked.
All in all I recommend this book to anyone who might find the idea of the world's most patient pseudo-time travelers interesting. When you have endless lives it leads to the ability to take all the time in the world to accomplish your goals, and while that might sound like the set-up for a slow read I found it fresh and compelling. I look forward to reading more by Claire North (and her other pen names).