'A dark and haunting thriller. It creeps under your skin and doesn't let you go' Paula Hawkins, author ofThe Girl on the Train

What's the worst thing your best friend could do to you?

Admittedly, it wasn't murder. A moment's carelessness, a tragic accident - and two children are dead. Yours.

Living in a small island community, you can't escape the woman who destroyed your life. Each chance encounter is an agonizing reminder of what you've lost - your family, your future, your sanity.

How long before revenge becomes irresistible?

With no reason to go on living, why shouldn't you turn your darkest thoughts into deeds?

So now, what's the worst thing you can do to your best friend?