Contents: Ch. 1. Reason and belief -- Ch. 2. Can the universe create itself? -- Ch. 3. What are the laws of nature? -- Ch. 4. Mathematics and reality -- Ch. 5. Real worlds and virtual worlds -- Ch. 6. The mathematical secret -- Ch. 7. Why is the world the way it is? -- Ch. 8. Designer universe -- Ch. 9. The mystery at the end of the universe