Sonic Underground

Robotnik has his sights set upon Queen Aleena's crown jewel, which glows as it is moved closer her. Sonic, Manic and Sonia plan to recover the jewel from the merchant owner before Robotnik, not only to find their mother, but to protect her as well. The Hedgehogs acquire the jewel and begin their search, the glow becomes more radiant the closer they travel to their destination and their hopes of finding the Queen seem to be a tangible reality.

Sonic, Manic and Sonia find an abandoned baby in an alley and begin a search for the baby's parents. Manic grows particularly fond of the child and decides that instead of taking the baby to a shelter as Sonic and Sonia ordered, the baby would be more comfortable at the Underground sanctuary.

Sonic and his siblings travel to the outskirts of Mobius to recruit a tribe of nomads for the Resistance. The Hedgehogs van breaks down and they are saved by the tribesman. Once they return to the camp, Manic discovers that the chief has been roboticized, which is a secret that could have the chief banished from the tribe.

Sonic, Manic and Sonia invade Robotnik's lair to retrieve the Hedgehog crest. After the book is reclaimed, they discover that this book contains directions to a scroll that could be an important tool to overthrow Robotnik. The scroll is heavily protected, but Sonic leads the group in the right direction where they eventually encounter the royal Aman-Rapi.

The Hedgehogs latest quest to find their mother takes them to the prison tower where they encounter a masked stranger who insists he is family. This stranger is actually being used as bait for another attempt by Robotnik to capture them. The stranger creates a rift between the siblings, which leaves the Underground disbanded, vulnerable and ultimately trapped.

The Oracle advises the Hedgehogs to undertake a mission which could reveal answers about their future. Sonic, Manic and Sonia are thrown into a universe that almost seems to parallel their own, however in this dimension, they are not the in the Underground, the Hedgehogs are the rulers of Mobius. Confused by this world, they begin to explore and suddenly find themselves confronted by a corrupted version of themselves.