«Or She Dies» by Gregg Hurwitz

First Patrick receives DVDs in the post. They show footage of him and his wife washing, dressing, going to work - all taken by cameras hidden in his house…
And then the emails start arriving: ‘Tell No One. Go Alone. OR SHE DIES.’

Patrick's life is turned upside down. Suddenly, this is a matter of life and death. He must follow the instructions on the email if he is to survive…