What murky waters hide

National bestseller in Britain. Superhit on Amazon Kindle. How do you find a killer when you're still a child? My name is Billy. I live in a house on a cliff. And the cliff is on an island. I'm eleven. But I'm nothing like my peers. Because I'm a real scientist. Yes, yes. A marine biologist. And recently I had to become a detective too... It's all because that girl, Olivia, went missing. And the police couldn't do anything. They didn't find any leads. But I did. I was there that night. And I saw something important. And also: no one knows the local sands and rocks, marshes and caves better than me... You've probably never read anything like this. Billy's investigation has a special style. But soon the boy finds himself in the center of a web of lies and family secrets. His childhood detective game turns into a race for survival. He becomes the target of a killer he knows well. And now he must solve this case in order to save his life...