Michael Crichton is a very creative author as he writes about science and medicine in great detail. You may be familiar with Jurassic Park, probably his most famous book and the movie by the same name. His book Timeline includes time travel and adventure during the middle ages which he writes about vividly. He gives a new spin on time travel or at least different from what I imagined and his portrayal of the Middle Ages is more violent than I had ever envisioned. But it is a great story that grabs you from the beginning and keeps you engaged. This whole adventure starts out in northern Arizona.
Unlike Crichton's Jurassic Park DO NOT bother with the movie - it is not even close!