In her near future, time travel is possible, and historians take advantage of the technology to visit and observe events of the past. The main character is Kivrin Engle, a young student specializing in medieval history at the University of Oxford. She asks to be sent to 14th century England, just before the Black Death is about to ravage the country. Unfortunately, the technician operating the time machine is infected with a deadly influenza virus and, not thinking clearly, sends Kivrin to 1348 — 28 years later than her target date, which places her directly in the path of the Black Death.