Agent X has come a long way but has finally reached his destination of Trituna, a city under the ocean. In his submarine, he speaks to Trouty about a message from Doctor Robotnik, leading the fish to go and fetch their Zone Leader, Sharka Khan. Immediately, Khan comes over, eager to not miss the start of Kippernation Street. Agent X proposes a deal; if the people of Trituna rise up and defeat Sonic the Hedgehog, Robotnik will grant them two surface Zones to live in once the tyrant comes back to power. Khan scoffs, knowing they cannot live out of the ocean, but X produces a potion which will give them all the power to breathe in air. Keen to live somewhere not so damp, Sharka Khan accepts.
The next day, in the Beanson Coast Zone, Sonic is called to respond to a problem when a variety of sea creatures appear to challenge him. Dodging Eelton John's electric blasts, he smacks the eel against a rock, but is caught by Stara. Jaws Michael comes to finish him off, but Sonic throws his starfish captor into the shark, knocking them both out. Crab Sea Nesbitt proves to be just as useless, getting subjected to a vortex attack. It looks as if all hope is lost, until Sonic has to face the massive Jimmy Whale.
Sonic initially struggles against the heavyweight boxing champion of underwater boxing, but decides to speed off. Although the Tritunas think he is running away, Sonic is merely getting a run-up, launching a Spin Attack which knocks Whale back into the sea. The rest of them hurry back into the sea, realising that the potion they were given is beginning to wear off. Back in Trituna, the mob reveal to Khan that the potion ran out, leading Khan to believe that Robotnik was just using them. Khan vows to gain control of a surface Zone some other way, but they are all interrupted by the appearance of Sonic, who has taken swimming lessons. Wearing a suit made for him by Tekno the Canary, Sonic is able to use his usual abilities underwater, making short work of his foes. Soon after, Khan returns to his room where he begins to pack, planning to find a new kingdom to rule. As he attempts to pack, Sonic bursts in through the wall. He reveals to the others that Khan was about to leave, shirking his leader duties. They decide to sack Khan, never wanting to rule the surface Zones anyway (they'd get wet when it rains). With Khan gone, they decide to rule the Zone themselves, although Sonic isn't sure how successful that would be.
- Sonic has learned how to swim, getting rid of his biggest obstacle.