'Had it not been for my weakness, someone who is now dead could still be alive. That is what I believed and consequently lived with every day in prison.' It is the summer of 1938 and Phyllis Forrester has returned to England after years abroad. Moving into her sister's grand country house, she soon finds herself entangled in a new world of idealistic beliefs and seemingly innocent friendships. Fevered talk of another war infiltrates their small, privileged circle, giving way to a thrilling solution: a great and charismatic leader, who will restore England to its former glory. At a party hosted by her new friends, Phyllis lets down her guard for a single moment, with devastating consequences. Years later, Phyllis, alone and embittered, recounts the dramatic events which led to her imprisonment and changed the course of her life forever.