The book starts without a cute meet, so I felt a little like I was dropped into a show where the story was already in progress. Rose and Stephen were neighbors/kind of friends when the book opens. I liked Rose, but she needed a longer book to be fully fleshed out character and to create a more believable change in her mind about falling for Stephen. Stephen first made his appearance in the previous book, so I was familiar with him. Rose is a math genius, Stephen is an expert in math puns. I really liked that this was another science-based plot, although it did have a feel of repeating Violet's and Sebastian's story from earlier in the series.
One thing about the story line that kept me from connecting to the romance was that Rose threw around her race and gender as the reasons why her life was much harder in Victorian England than Stephen's and why she had to be extra careful about the choices she made concerning marriage, children, work, and performing in society. I don't doubt that 1880s England was hard to live in when you are from a minority group, especially as a woman. Stephen realized how her race (especially) influenced every social interaction she has when he witnessed the doctor being racist to her and her sister. No mention of how Rose saw how hard living in Victorian England was for Stephen, an Irish Catholic - not exactly a welcoming environment. The Irish (especially the Irish Catholic) were not considered "white folk" until the 20th century; during the time of the story, they were very much "other". I felt that if Rose had a chance to see how life is as an Irish Catholic, like Stephen saw how living was for Rose as a black woman, there relationship would have had a deeper understanding to it.