Mark Williams was a master thief and a close friend of Lupin's. As his dying wish, he asks Lupin to return all of the great treasures he stole. The catch is that Lupin only has a few days to do it! If he's successful, he'll be able to obtain the Trick Diamond, a gem with a secret connected to Gaudi's Sagrada Familia in Barcelona. Lupin fights to make the deadline and get the diamond, with or without help from Jigen and Goemon!