In High Places
Harry Turtledove
 The book focuses on the relations between Christians and Muslims, as well as slaves and masters, in the medieval society through the eyes of Annette, an eighteen year old time traveller from the late 21st century who poses as the daughter of a Muslim merchant and who is captured and sold into slavery. It is also the first book in the series to concentrate more upon the late 21st century origins of the Crosstime Traffic organization.