Set in the same world of time-traveling historians as Doomsday Book and To say Nothing of the Dog, this book follows several historians who are going to various parts of England during the second World War, in order to observe and study history as it happens. At the beginning of the book, there is a flurry of activity as students are running around Oxford trying to get in touch with Mr. Dunworthy (or avoiding him, for fear he'll change his mind and decide their trip is too dangerous), getting their props and outfits for the period and place they'll be going, memorizing or getting implants of vital knowledge they'll need to do the research they intend or to stay safe while they're there. There seems to be something going on with the time-travel lab-- assignments are getting shuffled around and re-ordered, drop dates are getting moved up-- but the characters we follow aren't privy to whatever it is that might be causing this, and for the most part are so anxious to get out on their trips that they aren't worried too much about the bigger picture. As the novel progresses, we follow three main historians: Merope, who is working as a servant in the country where London children have been evacuated; Michael, studying the heroism of ordinary people, plans to go to Dover as a reporter so he can interview the men involved in the evacuation of Dunkirk; and Polly, who is going to London to work as a shop girl so she can study the behavior of Londoners in the bomb shelters during the Blitz. Of course, for each of them, something goes wrong that changes their assignment and their time in the past.
