I should start by acknowledging that this is such a clever and ambitious book. A story within a story, it introduces us to a mathematician who has written a collection of murder mysteries exploring the formula of the genre and a publisher interested in re-releasing them but, as in the stories he has written, not all is as it seems. 

I found the premise engaging and the overarching story incredibly intriguing and hard to predict. However, aside from one or two of the short stories which really drew me in, I found myself racing through a lot of them to get back to our protagonists in the present to keep unravelling their own mystery.

I also found it slightly hard to keep up without intense concentration when we revisit and rewrite the endings of every story later in the book.