Mario and friends finally uncover the truth behind Nimbus Land as Mallow learns that he really is the missing prince! After sneaking into the castle disguised as a statue, the party faces off against Birdo, chases down Valentina and Dodo, and reunites Mallow with his royal parents. With Nimbus Land saved, the search for the Star Pieces takes the crew straight into Barrel Volcano, where new enemies, upgraded gear, and a massive dragon battle stand between them and their next star. And just when victory seems secure, some unexpected visitors arrive to make things interesting…