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

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

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

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

A homecoming is interrupted for Sonic, Sonia and Manic when Sleet and Dingo arrive to collect back taxes after returning to their birthplace.

A captain of the Queen's guard is captured before he can reach the secret rendezvous where he was to meet Queen Aleena.

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

Robotnik has his eyes set upon Queen Aleena's crown jewel, but Sonic, Manic and Sonia plan to retrieve the gem before Robotnik.

Sonic becomes aggravated that maybe their efforts of fighting for freedom seem pointless. Sonia suggests that they go to the Oracle for advice.

As Sonic begins to chow chili dogs for a snack, he finds a message in the sack from his mother urging him to head to Speedster Island.

When S and G rocket to outerspace to mine a radioactive mineral from asteroids, Sonic and Tails stow away. Through a blunder by the robots, all are stranded in space, and Robotnik tries to blow all of them out of the stars.

Robotnik captures a Kangaroo named MacHopper, and uses his "brain-wipe-reprogramming-computer" to transform him into a resourceful demolitions expert (Ala MacGiver).

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.

A captain of the Queen's guard is captured before he can reach the secret rendezvous where he was to meet Queen Aleena.

Robotnik has his eyes set upon Queen Aleena's crown jewel, but Sonic, Manic and Sonia plan to retrieve the gem before Robotnik.

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

Sonia discovers that the watch she received from her friend is actually a monitoring device for the Robotnik Intelligence Agency.

The Hedgehogs find out that Sonia has inherited a castle. She basks in the idea of having a castle for headquarters.

As Sonic begins to chow chili dogs for a snack, he finds a message in the sack from his mother urging him to head to Speedster Island.

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

Sonic, Manic and Sonia find an abandoned baby in an alley and begin to look for the baby's parents. Manic becomes very fond of the child.