At first I thought this book was a little too hard science fiction with the overuse of numbers and jargon. Too much time on establishing medical parameters, etc. It was distracting from the story, and not completely necessary to establish a foundation.

That soon receded though, and then I was hooked, wondering if this young history scholar would be stuck back in medieval times while people in her time were dropping from a deadly flu.

One thing that dated the book was the reliance for plot on not being able to get a telephone line in a crisis. Cell phones already existed at the time of the book's publishing, though I could understand not imagining how ubiquitous they would become so soon.