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 next seven days, the Birches are locked down, cut off from the rest of humanity--and even decent Wi-FI--and forced into each other's orbits. Younger, unabashedly frivolous daughter Phoebe is fixated on her upcoming wedding, while Olivia deals with the culture shock of being immersed in first-world problems. As Andrew sequesters himself in his study writing scathing restaurant reviews and remembering his glory days as a war correspondent, Emma hides a secret that will turn the whole family upside down. In close proximity, not much can stay hidden for long, and as revelations and long-held tensions come to light, nothing is more shocking than the unexpected guest who's about to arrive...