The summer publishing season seems always to include a thriller that leaps to the top of the best-seller charts and stays there until the fall–when readers get serious and return to school and work. The Da Vinci Code is this year’s winner, sitting at the top of the Amazon.com ratings this week and listed at second place in the New York Times hardcover fiction list. The book was on the top of that list last week, and it has made the list for 18 straight weeks. Not bad for a book with a seemingly unmanageable mix of plot structure, conspiracy theories, and mountains of detail about Catholic orders, renaissance art, theological heresy, and theoretical mathematics. Hooked yet?