Socialite Lucinda Oliver planned a lavish celebration for her 40th birthday - a weekend escape at a coastal town with her sister Stella and her closest friends. The weekend was to end with a blow-out party and a special announcement, one Lucinda had been dropping hints about for weeks. But before Lucinda could reveal her secret, she went missing. And now, six months later, her car has been found submerged in the Atlantic Ocean. Devastated, Stella decides to gather Lucinda's friends once more, in that same coastal town - the first time they've all been together since her disappearance. Haunted by the argument she had with her sister the last time they saw each other, Stella is reluctant to revisit her memories. But then she begins to suspect that one of the group knows the truth about Lucinda's accident. Which one of them is lying? Stella vows to find out.