One letter a week for fifteen years. 780 identical white envelopes brimming with my sister’s darkest secrets. All the intimate details of a life as different to mine as could possibly be.

I read each letter slowly to make sure I understand it perfectly, one day very soon it will be a matter of life and death…

At the end of each letter, after signing her name, there is always one final sentence:

Don’t forget to burn this letter.

I’ll let you decide if I do…

A jaw-dropping psychological thriller that you will read in one sitting. If you loved dark, twisty thrillers like The Girl on The Train, The Couple Next Door and Friend Request, this unputdownable novel will have your heart racing long after you’ve finished reading.