Sonic Underground

Robotnik announces that he will marry Queen Aleena in a plot to become the king of Mobius.

Argus, a captain of the Queen's guard, is captured by Sleet and Dingo before he can reach the secret rendezvous where he was to meet Queen Aleena.

Sonic, Sonia and Manic return to their birthplace, Mobodoon, a beautiful, festive town.

Sonia travels to east Mobius to visit her friend Mindy at the LaTour estate.

Sleet and Dingo plan to collect the taxes owed to Robotnik from the Duke of Velcronia but keep it for themselves.

The sinister Robotnik blackmails Cyrus, an old friend of Sonic's, by holding his father hostage.

On a trip to Port Mobius, Sonic, Manic and Sonia are told that ships are sinking due to the Mobian sea-beast.

Queen Aleena's royal journals are rumored to be buried under a palace in the city of Tashistan.

While lost in the wastelands of Mobius, Sonic, Manic and Sonia stumble upon an oasis called Lake Valley Resort.

Sonia is invited to a debutante ball, but before she can be officially announced to society, she and her brothers, Manic and Sonic have an important mission.

Robotnik organizes a track meet to lure Sonic into a trap.

The Hedgehogs receive a message they believe is from their cousin.

The Hedgehogs steal historical artifacts of Mobuis from Robotnik before he can pawn them off at an auction.

A faction of the Freedom Fighters is wiped out by a swarm of metallic fly-bots.

A speed enhancing fluid deemed Sonic Tonic is created by Robotnik to make him as fast as Sonic so that he may finally catch him.

The Hedgehogs converge on the Floating Island, in their latest attempt to find their Mother.

Sonic becomes frustrated that maybe all of their efforts of fighting for freedom seem futile.

Robotnik has his sights set upon Queen Aleena's crown jewel, which glows as it is moved closer her.

Sonic, Manic and Sonia find an abandoned baby in an alley and begin a search for the baby's parents.