Four friends. Twenty years. One powerful secret. Everyone remembers where they were on 31st August 1997 the day Princess Diana died. Sophie Emily Amy and Melissa certainly do -- a beautiful cottage in Southwold at the start of an annual tradition to have a weekend away together. Every year since the four best friends have come back together. But over time the changes in their lives have led them down very different paths. And its when those paths collide that the secrets theyve been keeping come tumbling out. One Day meets Big Little Lies in this unputdownable read about four friends one long-buried secret and the histories we all share.