Book excerpt: When nerdy cruciverbalist Harvey Beerbaum throws a birthday bash for Cora Felton at the Bakerhaven Library, it's no surprise that the centerpiece, a huge cake decorated like a crossword puzzle, is a complete bust--until a corpse thrown from the second floor stacks hits it dead center and fills in 14 down. Cora may hate birthdays almost as much as she hates crossword puzzles--but when it comes to solving crimes, no one can hold a candle to the Puzzle Lady.