For me, the toughest layout would be any filming day with the "floating green tubes and plank" moat. That said, episodes "Discarded Seal of Ivan the Terrible," "The Missing Portrait of Hans Holbein," and "The Dried Apple Half of William Tell," were the toughest layouts. I also agree with, "Lucky Pig of Amiela Earhart" and "Ponce de Leon's Water Fountain of Youth, and I found "The Golden Goblet of Attila the Hun" pretty hard too.