**3.5 stars rounded up**

This book started out so strong. It was an incredible concept with likeable characters, and felt very tense and heart-wrenching at the same time. I was hooked from the beginning in this futuristic world with the terror of humans having destroyed the world, and the ability to alter our genes and DNA. It's a scary concept to think about. However, towards the middle of the book this turned into Logan's wild goose chase to find Kara and stop her from following in their mother's footsteps and finishing her plan for the human race. It got incredibly science-y, to the point where it felt like it was taking away from the plot. I don't have an issue with lots of scientific jargon or concepts, I read Dark Matter and Recursion and they were both 5 star reads for me, but this one just felt like too much. Overall it felt like a whole lot of build up for not a whole lot of pay off. It felt a little unfinished at the end. The epilogue made me a little emotional though, when Logan finally got to see his family again. I was happy to see he still got to be in his daughter's life, at least for a little while. The compassion upgrade seemed a little forced and random at the end, since throughout the entire book Logan is trying to stop Kara from upgrading the human race, but not really having another plan to try and fix it until much later.