Once again Liane Moriarty uses her unique, razor-sharp observational skills to sift through the emerging fault lines of seemingly happy families.

If only they'd said no....

What if they hadn't gone? That's the question Clementine can't stop asking herself.

It was just a backyard barbeque. They didn't know their hosts that well. They were friends of friends. They could so easily have said no. But she and her husband, Sam, said yes, and now they can never change what they did and didn't do that beautiful winter's day. Six responsible adults. Three cute kids. One yapping dog. It's a normal weekend in the suburbs. What could possibly go wrong?