Like most dog lovers, Missy's owners think she is irreplaceable - and they are rich enough to do something about it. Rescued from a San Francisco dog pound nearly 13 years ago, Missy is now at the centre of an audacious $2-million private cloning programme. James Langton, who has followed the project since its inception, is the only journalist to have taken Missy for a walk and thrown her a stick. In telling her story, he goes back 100,000 years to the very beginning of man's relationship with his dog.