In High Places: A Novel of Crosstime Traffic, by Harry Turtledove, is an exciting science- fiction adventure. Khadhija, the daughter of a wealthy Muslim Moorish merchant, is not all that she seems to be, and neither is the world that she is currently in. Khadhija is actually teenager Annette Klein, from the 21st century United States. She and her family are working for Crosstime Traffic, a business that trades merchandise from the alternate timeline- a world where history has taken a different path- to their modern timeline. In this alternate world, Europe is still engulfed in the medieval Dark Ages and greatly contrasts to the "home" timeline. For example, technology is basic, and the Muslims rule and occupy most of Europe, which is disunited into small states. The most significant difference is that in the alternate timeline, slavery still exists without any controversy. Annette and her family are preparing to return to the home timeline, so they travel in a caravan to locate the Crosstime Traffic portal that will send them home. However, bandits capture Annette, her local friend Jacques, and other travelers, and sell them all as slaves. Separated from her family, Annette's situation becomes even worse: her captors take her and the other slaves and transports them through an unauthorized Crosstime Traffic portal into a land ruled by Khadhija's own people. She must escape, but it seems as if she will be a slave forever.