The fabulous new novel from the Sunday Times bestselling author of RSVP and STAY CLOSE TO MEWhat if everything you ever wanted was not enough?Martha Lamont has it all: a passionate marriage, two well-adjusted children, a lovely home and a high-profile job as a showbiz interviewer for a major national newspaper. Her gorgeous husband, Jamie, is happy being a stay-at-home-dad while she pursues her career. But appearances are often deceiving. One day, Martha makes a discovery that rocks the very foundation of her world and she begins to question everything she thought she wanted.Then, during an interview with a famous actor, Charlie Simmons, Martha finds herself pouring her heart out. And soon their friendship turns into an intense relationship... Now, Martha must make the toughest decision of her life. Does she fight to keep the life she loves? Or are some betrayals just too big to forgive?PRAISE FOR HELEN WARNER'Four women, one wedding...

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 it's when those paths collide that the secrets they've 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.