Mario and Sonic (episode)
From the Super Mario Wiki, the Mario encyclopedia
Mario and Sonic (also referred to as Heroes Episode 1 and Heroes 1) is the first Heroes episode in the Story Mode of the Nintendo 3DS version of Mario & Sonic at the London 2012 Olympic Games. The episode is unlocked after completing both The Mysterious Thief and Enter Bowser?!, and unlocks The Secret of the Fog upon its completion. This episode's completion is required to unlock the Story Mode cleared badge.
Mario, Luigi, Toad, Sonic and Tails arrive at the British Museum. Toad wonders if Sonic and Tails are Fog Imposters, while Tails theorises that Mario and Luigi must be the real characters as Toad is with them. Mario, Luigi, Sonic and Tails approach and greet each other, and Toad explains that he thought that Sonic and Tails were Fog Imposters. As Toad is explaining their situations with the Fog Imposters, Fog Imposters of Mario, Luigi, Sonic and Tails emerge from the gates of the museum, scaring him. Mario, Luigi, Sonic and Tails challenge the Fog Imposters to an event to defeat them.
The Fog Imposters disappear upon their defeat, and Toad concludes that he, Mario and Luigi know roughly the same amount of information about the Phantasmal Fog as Sonic and Tails after Tails suggests that they look for a Fog machine. Toad also explains that he heard that Dr. Eggman was around the British Museum. Mario and Sonic open the museum's gates, and the group head into the museum's courtyard.