"Agent Arthur's Mountain Mission" is the Usborne Puzzle Adventure that never was. The Puzzle Adventure series started in 1985 with the publishing of "Escape from Blood Castle", and since then 24 further books were written and published worldwide in more than 90 languages. Agent Arthur starred in no less than 5 adventures, and was due to appear in his sixth and most ambitious adventure yet - "Agent Arthur's Mountain Mission". A detailed plot outline was written and a cover illustration was commissioned, but due to lack of perceived interest at the time in 1996, Usborne decided not to go ahead with the book. Please sign this petition if you would like to see the book finally written and published.