For over a thousand years, the people of the underwater city had no contact with the surface world. This changed when a mission to the Floating Island, carried out by Sonic the Hedgehog, Porker Lewis and Ebony, went wrong and their machine began to overheat (thanks to The Power, the city's power source). The heroes were forced to abandon their ship but were rescued by the city's inhabitants. Sonic was left confused, believing that they were Drakon Prosecutors, but he was soon given an explanation.
The trio were taken to the Power, a ball of Chaos Energy that powers the entire city. Being in close proximity to the raw energy began to transform Sonic into Super Sonic, but Porker acted quick enough, pushing Sonic out of the room. The city's elder then agreed to help Sonic on his mission to the underwater city, providing him with an air bubble and transport to the Floating Island. Porker and Ebony remained in the city, with Porker maintaining radio communication with Sonic. Unfortunately, an ill-advised Spin Attack from Sonic destroyed the radio, losing him contact with the city. Worse still, using the city's sensors, Porker deduced that the shields had only ten minutes left before giving way. Ebony suggested using a bubble of the Power to turn Sonic into the "good" Super Sonic. The Chaos Energy arrived, turning Sonic evil and releasing Tikal in the process.
The situation gets worse when malfunctioning Guardian Robots breach the island's forcefield and swim to the surface. Porker and Ebony decide to teleport themselves into the Emerald Chamber to see the extent of Sonic's transformation.