A silent young boy, a man like a rat, and a plague of mice-Cat has her work cut out for her. It's hard enough for Catriona, an ordinary modern woman, to get used to living in a magical medieval world, even without having mice pop up at every turn. Good thing Cat isn't as squeamish about rodents as her friend Nicky, who has her own issues to cope with back in the regular world. What does the man with the twitchy nose want with young Ben, Nicky's ward? And does the mouse plague back in Ruph have anything to do with the new apprentice Cat's husband has taken on-the boy who won't speak? This is Book Number Two in The Septimus Series, begun with SEVENTH SON.