This is one of those books you think about after you've had to put it down. Then you look forward to having enough of a time gap to get back to it.  It drags you in for hours after that - I think I only had three sessions with it.

It starts with an ordinary-ish family going to the beach in an ordinary way.  Once on the beach, Gin's world unwinds... an apt term she gives to the way her world falls, not just apart, but into multi-dimensional strands.

We get thrown with her into historical times, and then into the future, or is it just a parallel universe?

We are following the clues to what is going on, just as Gin is, so it's part detective story as well.  And, as with all good detective stories, superior knowledge is being bandied about to help us readers get one step ahead of Gin. A one-sided commentary on Gin's progress comes from someone (or something) reporting to... someone else. It's intriguing!

This book delves into time and space on a cosmic scale. It considers how the universe develops, and whether our universe is colliding with another, and what might happen as a result. Or maybe it has already happened, and some entity is stuffing dark matter into it so as to dampen the effects of this extra-universe intrusion. Maybe we should do some statistical analysis on the Big Bang and see...

It's a very clever book, very well written, and I didn't get lost with either the people or the places involved. Even better, I didn't get lost in the science. I may not fully understand string theory and the like, but I've got up to date enough to hang in with the terminology.  I suggest that's a must if you want to enjoy the book.

I loved this book. But there is the indication of another book in the series, and I'm not sure that I want that. Minds should only be blown once every few years, perhaps, and this was mind-blowingly excellent.