There is something to be said for a book you finish in 24 hours, not because it is slender in any way but because you shut out The Intrusive World in order to spend the time with it.
This is such a book.
This is a novel full of characters you root for, and full of a mystery--not just about the plot but the quest to unfold the mystery you can sometimes be to yourself.
So, when someone says, "Hey, read this book about time travel," don't be put off. It's handled deftly. The time travel isn't a deus ex machina, it's interwoven with the plot in a believable, grounded in reality sort of way. Which, if you read the book, is not a unlikely as it may sound.