Take your brain for a jog around an entertaining collection of wildly clever twisters, illustrated with zany and delightful drawings. Many play with clues that are numbers, letters, or words. Others use tricky visuals to tease the mind. ALL are favorites of a world-renowned puzzle master—and they're tougher than they look, to provide a really enjoyable challenge. Try this one, just to warm up your wits and whet your puzzle-solving These letters, when properly understood, stand for a common liquid. Name it. Or—complete a crossword puzzle by filling blanks with words that mean the opposite of the clues, finish a joke by making up the punch line, and lots more!

1. H to O or H2O, the chemical symbol for water—two atoms of hydrogen combined with one atom of oxygen.