Introduction; 1. Good extender sequences; 2. Fine structure; 3. Squashed mice; 4. Ultrapowers; 5. Iteration trees; 6. Uniqueness of wellfounded branches; 7. The comparison process; 8. Solidarity and condensation; 9. Uniqueness of the next extender; 10. Closure under initial segment; 11. The construction; 12. Iterability; References; Index of definitions; Index.