Katherine has lived her life by the book, and she has plenty to show for it: the perfect job, the perfect house, the perfect car, the perfect boyfriend. She has earned the respect of her friends and colleagues. Nothing could possibly bring her down, not ever.

Oh, except when she makes one split-second decision that provokes an onslaught of abuse from a million faceless internet strangers. Surely, though, that won't change her life forever?