Several children have gone missing in medieval Cambridge and the townfolk have decided to blame their Jewish neighbors. The king is mad because keeping the Jewish community locked away in the castle is cutting into his income, so he hires a doctor through his cousin, the King of Sicily. The person who shows up is a female doctor, something that's basically considered witchcraft in England, and she is accompanied by a Muslim companion and a Jewish companion. Mind blowing. She's brilliant and is immediately leaping into action, while pretending she's not the doctor. She investigates and in the process we learn about the community and the politics. This was really good...with the slight caveat regarding the identity of the killer. 

CW: antisemitism and child death