From the bestselling author of The Family Next Door comes a new domestic page-turner about that trickiest of relationships and what happens when it all goes wrong**PREORDER THE GOOD SISTER NOW**'Fiction at its finest' Liane Moriarty, Number One bestselling author 'Perfect for fans of BIG LITTLE LIES' - Library Journal She has never approved of you.But it's when her body is found the secrets really start to come out ... From the moment Lucy met her husband's mother, Diana, she was kept at arm's length. Diana was exquisitely polite, and perfectly friendly, but Lucy knew that she was not what Diana envisioned. Even so, Lucy wanted so much to please her new mother-in-law.That was five years ago. Now, Diana has been found dead, a suicide note near her body. Diana claims that she no longer wanted to live because of a battle with cancer. But the autopsy finds no cancer. The autopsy does find traces of poison and suffocation.Everyone in the family is hiding something. But what? And where will the secrets stop?With Lucy's secrets getting deeper and her relationship with her mother-in-law growing more complex as the pages turn, this new novel from Sally Hepworth is sure to add to her growing legion of fans. 'The best book that I have read in a long time... Would make an amazing tv series. Does not disappoint!' Reader Reviewer'Prepare for Gone Girl-level twists' Refinery29'Wow!What a conclusion!' Reader Reviewer'Brilliant characterisation, great story, a genuine five star read' Reader Reviewer'I read this book in just two days because I just couldn't put it down' Reader Reviewer'The Mother-in-Law is indeed twisty and suspenseful, but even more than that, it's clever and nuanced' Kelly Rimmer, bestselling author of Me Without You