What would you do if your deepest secrets were held to ransom? Jenny Kleeman investigates one of the world's most audacious hacks.

When a shocking data breach takes place at a Finnish psychotherapy service, the nation's darkest secrets are held to ransom by a faceless hacker. He calls himself ransom_man.

We all have some thoughts we'd never write down. Now, just imagine that a criminal had got hold of those thoughts, and was threatening to publish them for all the world to see if you didn't pay to stop him. Jenny finds out what kind of person is prepared to terrorise a nation like this, and the lengths people will go to fight back. On the way, she'll discover that the origins of this dark crime stretch far beyond Finland. Her extraordinary quest leads her around the world and to unexpected places, bringing Jenny face to face with victims, investigators, police and notorious hackers themselves.

It is a cautionary tale about something that could happen anywhere, to any of us, again and again.