Chocky

At first they thought that Matthew was just goining through a phase of talking to himself. And like many parents, they waited for him to grow out of it. But as time passed it became worse, not better. Matthew's conversations with himself grew more and more intense. It was like listening to one end of a telephone conversation while someone argued, cajoled and reasoned with another person you couldn't hear or see. Then Matthew began doing things he couldn't do before. Like counting in binary code mathematics. So he told them about Chocky, the person who lived in his head. Whoever or whatever Chocky was, it wasn't childish imagination. It was far too intelligent and frightening for that.