Sonic returns to his planet after releasing the seven chaos emeralds into space.

Cosmo reveals the mission of the Metarex.

Sonic is captured by the Metarex.

Sonic and the others see through Eggman's trick.

Sonic and friends are back on the hunt for Chaos Emeralds.

As Sonic crashes with Eggman onto a jungle planet, Amy rushes out to find him, and Cosmo and Cream follow.

Chuck finds a way to teleport material objects to Sonic's world, and Vanilla asks the Chaotix to help wend them to Chris.

The crew of the Blue Typhoon go emerald hunting on a deserted planet.

A Metarex fleet lead by Scarship sets out to destroy Eggman and Sonic with its might.

After the battle with Metarex's Scarship, the Blue Typhoon crashes onto a strange planet.

Sonic and Eggman agree on a joint effort to retrive the last two Chaos Emeralds hiden inside a Metarex fortress.

Sonic squares off with Dark Oak and his army of Metarex.

Vector comes up with a scheme to play match maker for Cosmo and Tails.

As they travel through the Intergalactic Cloister, Sonic and the others battle Yellow Zelkova.

Sonic and friends come across a barren planet with 500 Chaos Emerald signals coming from it.

While traveling through space, Dr. Eggman and his forces come across a group of humans battling the armada of Pale Bay Leaf.

Sonic and the others finds a race called Marmolians and head to their home planet.

The Chaotix trio tries to aide Sonic and his friends as Metarex hunts for them.

The Blue Typhoon arrives at a planet, but Yellow Zelkova attacks the Blue Typhoon.

Shadow invades the Blue Typhoon, trying to kill Cosmo for reasons unknown.

When the team discovers that Cosmo's brain is emitting a signal to the Metarex, they plan on trying to eliminate the signal, except that the signal is connected to the part of her brain that translates sounds and sight. While Tails and Cosmo are torn about this, Knuckles pushes for the surgery.

Sonic and the others chase after Dark Oak to galactic coordinates 0-0-0, where a thousand-year prophecy will bring their plan to fruition.

After Sonic falls into the watery planet, the gang struggles for a way to rescue him and defeat Dark Oak.

The giant seed finally reaches the final stage of its metamorphosis, and Cosmo steps in the battle to stop it.

After the galaxy is saved, Sonic and his friends recalls memorable moments and anticipate their future.