South Islands in BIG trouble! Defeat after defeat after defeat - Dr. Robotnik's going right for the source: The Chaos Emeralds themselves!! He's already gotten the red one, somehow throwing the others into a parallel universe. The shift in power balance has caused South Island to start sinking into the ocean! It's up to Sonic and Tails to collect the remaining Chaos Emeralds and recover the red one from Robotnik before South Island and all its inhabitants go for a looong swim...