Invisible Ink Yes & Know 8-88 is yet another title in the absorbing Invisible Ink series of unique puzzle and game books. You and your Invisible Ink Pen provide the brain power to solve puzzles, answer questions on dozens of topics, and win at popular paper games like Hangman, Bingo, or Fleet. Great for travel, quiet time, and classroom fun, Invisible Ink books hide surprises and secret information on every page and provide hours of entertainment for kids and adults alike!