Scotland Yard and Bletchley Park Puzzle Books Since it opened its doors in 1829, Scotland Yard has been synonymous with top flight detective work. This ingenious collection (HAL352 - sold separately) allows armchair detectives to solve dozens of the most challenging cases from the Scotland Yard archives. Bletchley Park Brainteasers (HY9512) contains the original puzzles used by British Intelligence to identify the individuals who would eventually defeat Germany's Enigma machine. Paperbacks, 280 pages.