So historians in 2054 have time travel tech and use it to travel back and study the past. In this story a young historian, Kivrin, convinces the history department at her college to let her travel back to 1320, but what they don't know is that she has been infected with a new strain of flu. She is accidentally sent to 1348 when the Black Plague starts in Oxford where she is deathly ill for days and almost dies. In the present the new flu strain causes an epidemic killing many people before a vaccine is developed.
This is paralleled by Kivrin watching everyone in the village she is visiting die horrible deaths from the plaque. And Willis's description is pretty graphic. To make matters worse since Kivrin is sent to the wrong year she is almost lost in the past.
While this story was a little long winded with some of the descriptions, etc. the story is really good. It jumps back and forth between Kivrin in the past and the people in the present dealing with the flu epidemic and trying to figure out how to get her back. I wonder if Willis was having a crisis of faith while writing this book as she is very detailed in her description of how people in 1348 felt that God had abandoned them, all except Father Roche, the village priest and the last to die. Kivrin even had a recorder embedded in her wrist that was activated when she puts her hands in an attitude of prayer. Kivrin even at times railed against God about not taking someone and the railing against Him about just getting it over and putting someone out of their misery.
All in all a great story and highly recommended.