This book draws on the many excellent presentations at the meeting, G4G5, held in Atlanta on April 5–7, 2004. It commemorates the memory of two great puzzlers, Edward Hordern, a master puzzle solver and a great puzzle collector, and Nobuyuki Yoshigahara, a master puzzle designer.

Part I: Braintreasures 1. Chinese Ceramic Puzzle Vessels 2. Mongolian Interlocking Puzzles Part II: Brainticklers 3. Fold-and-Cut Magic 4. The Three-Legged Hourglass 5. The Incredible Swimmer Puzzle 6. The Butler University Game 7. Vive Recreational Mathematics 8. Godelian Puzzles Part III: Brainteasers 9. A Bouquet of Brainteasers 10. Sliding-Coin Puzzles 11. Underspecified Puzzles 12. A Cryptic Crossword Puzzle in Honor of Martin Gardner 13. Absolute Martin Part IV: Braintempters 14. A History of the Ten-Square 15. Configuration Games 16. BlackJack Stacks 17. Five Algorithmic Puzzles 18. Polyform Patterns 19. Another Pentomino Problem 20. Polyomino Number Theory (III) 21. A Golomb Gallimaufry Part V: Braintaunters 22. The Panex Puzzle 23. Upstart Puzzles 24. The Complexity of Sliding-Block Puzzles and Plank Puzzles 25. Hinged Dissections: Swingers, Twisters, Flappers 26. Part VI: Braintools 27. The Burnside Di-Lemma: Combinatorics and Puzzle Symmetry 28. Designing Puzzles with a Computer 29. Origami Approximate Geometric Constructions 30. Rolling Block Mazes 31. Constructing Domino Portraits