I enjoy when a book can take a concept and then build a world, religion, science and laws around that concept. Being able to do a deep dive and understand how this world operates with that concept operating at its core is a fun thought experiment.

Wesley Chu did an admirable job of taking the thought experiment of time travel and the implications it would have before, and after, it was invented. There is some fun science fiction elements and warnings about the implications of our technology.

I liked this book, until it deviated away from the concept that got my attention. Once the story settled in a single location and had Little House on the Prairie vibes my enthusiasm decreased. There were still hints of what I found initially appealing but it became second to Elise and the Elfreth.

I was entertained from cover to cover but the book wasn't what I expected, and that's okay too. Instead Chu took a different concept and explored the personal and survival element further.