Doomsday Book by Connie Willis
Doomsday Book was Willis's first full length novel set in what is now called the Oxford Time Travel series. However, it is the last I've read. (Actually, we listened on cd, starting on our recent road trip.) Each of the three books (I'm counting Blackout/All Clear, my favorite, as one book.) has a very different feel to it, different characters, some overlap, different periods of history, and need not be read in order. The basic premise of the series is that historians travel back in time to study history. So, yes, there is time travel, but it is also historical fiction. Very well researched historical fiction.
This is the darkest of the books, alternating between a young historian caught in the plague and her contemporaries in Oxford beset by an epidemic of their own. I won't say more about the plot, because it would spoil it for you. Often, when stories flip back and forth between two sets of events/points of view, I find myself wanting to rush through one to get back to the more interesting side, but that was not true here. Both stories held my interest, and the flipping between times was irregular, which added to the sense of uncertainty the characters felt.
I will say that I wished I'd been reading not listening, because the narrator's voices got on my nerves. Her Mr. Dunworthy sounded nothing like mine, and her whining voices were too authentically whiny. She also slowed the pace.