Six months have passed since Chaos Control occurred; instead of returning Sonic and company to their home world, The Planet KO-35 were brought here. Eggman and Bowser has also been strangely quiet during these six months, though they have gotten the Red Chaos Emerald, and G.U.N. is desperately searching for him. Then new characters, Big the Cat and his little friend Froggy show up (after appearing in Episode 1 and not appearing until now). They find the Purple Chaos Emerald but then Froggy swallows a blue blob and grows a tail. Big is confused, and Froggy swallows the Chaos Emerald and runs away. Chasing Froggy, Big runs into Chris and Cream (who are leaving their short visit with Lindsey and have been given the Yellow Chaos Emerald) who tells them about Froggy. Chris and Cream help him search for Froggy. Big, Cream, and Chris run into a monster named Chaos, a shape shifting water creature, and it begins its attack. Sonic and the Rangers appears and comes to the rescue, defeating Chaos temporarily. Eggman and Bowser then appears and tells Sonic, Mewtwo, Karone and his friends about Chaos and how each time he gets a Chaos Emerald (one of which Eggman has already), Chaos becomes bigger and stronger. Eggman grabs the Yellow emerald and gives it and his Red Emerald to Chaos, and Sonic, The Rangers, and Knuckles narrowly manage to defeat him. This is the first episode to be based on the game Sonic Adventure.