The first mistake
(Book)

Alice knows that life could have been different if her first husband had lived, but Nathan's arrival into her life gave her back the happiness she craved. And with her best friend Beth by her side, Alice can survive anything. So when Nathan starts acting strangely, Alice turns to Beth for help. But soon, Alice begins to wonder whether her trust has been misplaced. She doesn't know she's already made one mistake. And this time, the first mistake could be her last. -- adapted from jacket

Believing she has finally achieved happiness in her second marriage, children and best friendship with the most loyal woman she has ever known, Alice turns suspicious when her husband and best friend start disappearing for extended times.