Great hard science fiction! Second book in the series continues to get it right!
The second book continues the story of Ethan Cole and his family as they support his construction of the a device that can fold space time in four dimensions. This is a smart discussion of time travel that respects causality. I loved the discussion of twistor space based on Penrose research. I thought the family dynamic was a times a bit pedantic. While I appreciate how Watkins used that dynamic in the story, it was starting to get a bit repetitive. But the author used it build a real sense of love and support for their amazing son. I can't wait to see what happens next!