A Well-Timed Enchantment

It's bad enough that Deanna has to waste her summer in France and her only friend is a mangy black cat, but now she's staring hopelessly into a well, trying to figure out what in the world to wish for.
Before she can make a wish, the cat scratches her, her watch falls into the well, and then . . . so has she! Except that now she's in medieval France, the cat is a handsome young man, and her watch has the power to completely change history.
Maybe a quiet summer would have been nice?