Mark is a character appearing in Professor Layton and the Unwound Future. He is a frequent visitor of the Gilded 7 Casino. He tells Luke he is the owner of the Casino, but after solving his first puzzle he then tells them he is just there as a regular visitor. Near the end of the game the Gilden Seven Casino reopens. During this time Layton and Luke can then reenter the building and then they can get some puzzles from Mark and Harold.
Mark, even appearing near the end of the game, gives Layton and Luke a couple of puzzles during their time in Future London. The first puzzle he has to offer is "A Roll of the Die". The other puzzle is "The Marked Cup". Both of his puzzles involve gambling games and items.