"It's Christmas, and for the first time in years the entire Birch family will be under one roof. Even Emma and Andrew's elder daughter--who is usually off saving the world--will be joining them at Weyfield Hall, their aging country estate. But Olivia, a doctor, is only coming home because she has to. Having just returned from treating an epidemic abroad, she's been told she must stay in quarantine for a week--and so too should her family. For the...