Book excerpt: Find out what it takes to become a puzzle master. More than 500 IQ brainteasers--some of the most devious ever published--offer a challenge that will stretch anyone's analytic and lateral thinking abilities to the limit. The requirements for cracking these puzzles include a sharp mind, keen mathematical skill, and a supremely logical approach. Go through a group of grids, determine the logic in their organization, and decipher the missing pattern in the final one. Check out the time on four different watches, and then figure out what hour the fifth watch should read. Look at dominoes lined up side by side, and calculate what number should appear on the last domino to complete the series. Every puzzle is brainy fun.