Silvio lost his Duel, and was subsequently sent to the underground. In that place, Gong was arguing with the owner of the Underground Dueling Arena, Gallager. Gallager tells Gong, Silvio and Tsukikage about the rules of the underground facility, and how to get back to the surface. On the other hand, Tsukikage, whom managed to escape from the facility, speaks to Yuya about Declan and Reira's desires This episode is the 777 in the Yu-GI-Oh! franchise and feautures a special opening. (thetvdb.com)