After the events of Sonic 3, Sonic and his friends return from Earth to their home planet Mobius. Sonic has to search for his adoptive mother Longclaw along with Tails and Knuckles, Shadow returns and meets Rouge and Omega on a mission to find Robotnik's hidden treasure, Amy, Cream, and Big have to protect the Chao in the Chao Garden, Team Chaotix meet up with Silver and Blaze to find the trigger that will cause their world to crumble. Unbeknownst to anyone, there is an evil lurking in the shadows that will bring destruction and chaos to the world of Mobius! All teams will come together in the end and defeat it!
