A Rainbow In Fog
From the Super Mario Wiki, the Mario encyclopedia
A Rainbow in Fog (also referred to as Heroes Episode 3 and Heroes 3) is the third 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 Stop Dr. Eggman!, The Banana Incident and Corner the Koopa King!, and unlocks To the Ruins! once it is completed. This episode's completion is required to unlock the Story Mode Cleared badge.
Mario, Luigi, Toad, Sonic and Tails meet Omochao back at the Olympic stadium, which is now covered in rainbow colored Phantasmal Fog. The group is unsure how the fog has returned, as there are no more Fog machines around the stadium, and decide to look around and investigate. The group then hear a cry from the fog and head to investigate. Cream and Cheese are also in the stadium and wonder what is going on when they are approached by Fog Imposters of Mario, Luigi, Sonic and Tails, who challenge them to an Olympic Event. A red and yellow Shy Guy looking on are scared off by the odd behaviour of the group and leave the stadium. The real characters arrive to help Cream and Cheese, explaining what is happening and taking on the imposters.
The group defeat the Fog Imposters, causing them to once again disappear, and Cream and Cheese thank the group for saving them. Toad notes that they currently have no leads on the cause of the fog at the moment, until Omega, having recovered some more of his memory, suggests that they investigate at Stonehenge. As Tails was planning to head there anyway and the group had no other ideas, they decide to head for Stonehenge immediately, though Omochao hands Toad a walkie-talkie so that they can stay in contact should they need to. Mario, Luigi, Toad, Sonic, Tails and Omega head to Stonehenge, while Omochao, Cream and Cheese wait behind at the Olympic stadium.