Portal 2

With Natalie's marriage to Gareth in tatters, her life has taken a turn for the worse. After a night of heavy drinking, her world is turned upside down and she feels suicidal. Gareth appears to have moved on with his life and has started dating again, but a first date takes an unexpected turn and Gareth finds himself in a dangerous situation. Natalie is the only person who knows that Gareth might be in trouble, but she has a problem of her own when she starts receiving text messages from the phone of her dead lover Ryan.
What follows is a mystery of epic proportions that will leave the reader guessing right up until the final chapter and is an epic continuation of the Portal saga.