This is a snowy level set outside a large base, most probably Eggman's, complete with many large buildings and searchlights. Sonic, like in Crisis City, has another snowboarding area here, which is a homage to the Icecap stage from Sonic the Hedgehog 3.
- Sonic's Story (3rd Stage)
- After meeting up with Knuckles, and receiving a letter from Dr. Eggman threatening him to bring the Chaos Emerald he has, Sonic and the others set off to find Dr. Eggman's secret base, the "Aquatic Base".
- Shadow's Story (1st Stage)
- Shadow journeys to Eggman's base in search of Rouge, who has sent an SOS call after trying to locate and recover the Scepter of Darkness.
- Boss: Egg Cerberus
- Silver's Story (5th Stage)
- Uncertain whether or not Sonic really is this fabled "Iblis Trigger", Silver and Blaze journey to Dr. Eggman's base in search of some answers.
- Boss: Egg Genesis