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"Sub-Sonic" is the eleventh episode of the Sonic the Hedgehog television series. Despite airing as the eleventh episode of the series during the show's original run, it was initially produced as the twelfth episode of the series. It first aired on 27 November 1993.







The episode begins with a Snake Probe emerging from Dr. Robotnik's drilling plaform out in the outlands and digging down to an underground oil lake. Meanwhile, Robotnik contacts Snively, whom he asks about the progress on the oil retrieval. Snively replies that thirty-six percent of the oil has been extracted and that an increase to fifty percent is expected soon. Robotnik, however, is not satisfied with this and orders Snively to obtain much more oil, regardless of the fact that the drilling plaform has been working for ten days at full power. In the meantime, one of the Snake Probes enters some underground caves and awaken the Kraken, who was sleeping on his throne. The creature roars and jumps off his throne before walking away. Soon after, a Snake Probe begins to demolish the cave, cutting off the tributary of the river with green water with boulders from the collapsing cave. As a result, the green water spills up to the surface and leaks into the Great River.

Meanwhile, the Knothole Freedom Fighters are trying to plant trees, only for all of them to die. Sally and Rotor do not understand why this is happening, even though Sally has calculated the proper amount of sun, water and energized soil. Rotor then notes that it is not only the tree saplings that are looking sick, but the full-grown trees as well. Tails and Antoine then arrive with some fertilizer and the fox cub begins adding it to the sick saplings. As Tails asks why the trees are looking sick, Sally suspects that the pollution from Robotropolis is spreading farther and farther from the city. After Antoine finishes complaining about the smell of the fertilizer, dark clouds begin to gather. Noticing a storm is about to break out, Sally hopes that some rain will bring the trees back to life.

Meanwhile, Sonic is playing on his electric guitar and singing while having a fishing rod cast out from a wooden bridge over the Great River. Eventually though, Sonic stops his performance when a fish gets caught on his fishing hook. Sonic tries to reel in his catch, but the fish pulls him into the river with him. Sonic struggles with the fish, but it eventually escapes him and Sonic lands in the green water. Returning to his friends, Sonic tells them about his little adventure with the fish. Rotor is disappointed that Sonic did not catch the fish and Tails is delighted by the story. Antoine on the other hand does not believe Sonic's story. Sonic insists that he is speaking the truth before shaking a bit of green water out of his ear. This water hits a nearby flower, which immediately begins to grow in front of Sally. Everyone is amazed by the sight, but Sonic has no explanation for how that happened. He proceeds to knock some more green water out of his other ear, which lands on a tree sapling. At first, nothing happens, but soon after, the sapling grows into a full-grown tree. Sally wants to know where Sonic got the water from, and Sonic explains that he got it from the Great River, near their bridge. With this piece of information, Sally proclaims that they have to get more of it.

Soon after, Sonic, Sally, Antoine and Rotor are sailing down the Great River in Rotor's boat. During the cruise, Rotor tells Sonic that he would like to be a superhero like him instead of a nerdy handyman. Sonic knows what Rotor means, but he tells him not to worry about it because he is a great mechanic. Meanwhile, Antoine gets terrified when one of the logs in the river collides with the boat. Sonic instructs Antoine to calm down and enjoy the cruise, which he agrees to. Sally then notices trees dying on the banks of the river and expresses her concern that all the trees in the Great Forest are slowly dying. Sonic suspects that maybe the green water can help them. Immediately after, however, the boat is suddenly caught in a strong current. At the request of Sally, Rotor tries to control the boat, but the river proves too strong. The heroes are then dragged into a whirlpool and soon find themselves in an underground lake with contaminated water and mechanical garbage floating around on the water's surface.

Antoine is still afraid, but Sonic grabs an oar and tells him to calm down. As Antoine manages to control himself, Sonic continues to use the oars while Rotor gets to work on the boat's motor. Sally asks Nicole for a map of the underground lake, but Nicole has nothing of the kind on file. To make matters worse, Rotor has discovered that they have lost their boat's motor, which frightens Antoine. He is then forced to grab a third oar and use it to propel the beat, but he soon gets tired and starts complaining. Soon after though, a large, mechanical fragment appears in the heroes' path and is heading straight for them. Sonic and Rotor dig their oars into the fragment in order to push it away while shouting for Antoine to turn the boat. However, they do not receive an answer from Antoine, and the fragment eventually rams the boat, creating a hole in it. Eventually, Sonic manages to push the fragment away. However, when the heroes turn around, they see that Antoine has disappeared. They call for him, but do not receive an answer. As the trio of heroes continue their cruise, Sonic notes that they will find Antoine. Not long after, they enter a river with some seriously polluted and colorful water. Meanwhile, Sally and Rotor attempt to keep their boat from sinking by pouring out the water leaking in with their hats and boots while Sonic continues to paddle. They are then suddenly caught in another current that leads them towards a waterfall. The boat goes over the waterfall, but Sonic manages to jump out of the boat and push it against the stream. Eventually, Sonic succeeds in running the boat back up the waterfall and into a side branch on the main river. After Sonic gets back onboard the boat, Sally kisses him on the cheek and thanks him for both his daring rescue and his bright idea. Suddenly, however, the water around them turns pink and begins to boil, slowly breaking the boat apart. Fortunately, Sonic manages to grab onto the vines protruding from the cave's ceiling, and Rotor and Sally join him. With Sally and Rotor holding onto Sonic's legs, they manage to cross the lake via the ceiling.

Entering a cave with beautiful vegetation, Sonic, Sally and Rotor call for Antoine. Rotor fells that someone is watching them, but Sonic and Sally calms him down because they are only surrounded by plants. However, right behind the heroes, a fast-growing vine is following them. When Sally then approaches an interesting yellow flower, it suddenly bares red teeth and tries to bite her. Sonic comes to her aid however, and when the flowers try to bite him from both sides, Sonic begins rotating like a top at high speed. He then circles around the flowers, causing them to get tangled up by their stems. Although the flowers have been defeated, Rotor notices that Sally has disappeared. Sonic and Rotor calls for her, but they do not receive any answers. As they move on, Sonic and Rotor reach an underground throne room. The smell of this place reminds Rotor of Robotropolis. As they approach the throne, Sonic hears a sound and tells Rotor to stay. Going to investigate the sound's source, Sonic calls out for Sally and Antoine. Meanwhile, behind him, a mysterious shadow begins to appear. Eventually, Rotor's hears Sonic yelp and goes to investigate, only to discover that Sonic has been caught by the Kraken. Sonic tells Rotor to run away, but Rotor stumbles. The Kraken tries to grab him, but Rotor eventually falls into a hole that was previously covered by debris.

The Kraken begins to ask Sonic what he has done to his underground world, but Sonic replies that that he has no idea of what he is talking about. As such, the Kraken takes Sonic with him to show him what he means. Meanwhile, Rotor is rolling down the hole until he is deposited into the underground river with the green water. Recognizing the water, Rotor realizes that the water is the reason why this part of the cave is so overgrown. His attention is then drawn to the stones falling from the cave ceiling and blocking the green water's river. Scattering the stones, Rotor manages to unblock the river and allowing the green water to flow again. He also takes a sample of the green water with his canteen before departing. Meanwhile, the underground roots come into contact with the reflowing green water, and the trees in the Great Forest come to life again.

At the same time, Sonic, Sally and Antoine are immersed in contaminated water. With their situation looking grim, Antoine begins blaming Sonic for their predicament because he did not save them even though he is supposed to be the hero. Meanwhile, Sonic is unable to free himself from the contaminated water, just like his friends, and Antoine gets scared when a mutant crocodile passes by. To make matters worse, Sally notices that the water level is rising. Meanwhile, Rotor has reached one of the underground lakes. Examining the dirty water, Rotor detects oil. He then sees a reflection of light in the water's surface. Looking up at the ceiling in the cave, he sees a Snake Probe emerge from it. The Snake Probe proceeds to fire lasers at Rotor, but he manages to dodge it and escape through a side tunnel. He then hears Sonic, Sally and Antoine calling out to him for help. After Rotor arrives in the cave where the others are, Sonic begs Rotor to pull out the Power Ring in his backpack. Putting his canteen with the green water aside, Rotor grabs a board and makes a bridge out to Sonic. Before he can reach Sonic however, Rotor is grabbed around the leg by a green tentacle that begins dragging him towards the water. Fortunately, Rotor manages to hold onto a stalagmite and make the tentacle release him after kicking it into the ground several times. After the tentacle lets go, Rotor quickly runs over to Sonic and pulls out the Power Ring from his backpack. Sonic proceeds to grab the Power Ring and runs out of the water. Sonic then rescues the sinking Sally while Rotor pulls out Antoine in the last moment.

As the heroes recover their breaths, Sonic thanks Rotor and calls him a hero. Sally also gives Rotor a kiss on the cheek and Antoine salutes him. Their moment is interrupted, however, by an earthquake, and Rotor tells his friends about Robotnik's Snake Probes which the doctor is using to extract oil. The heroes proceed to run out of the crumbling cave, only for the Kraken to block their path. The Kraken tells them that they will not escape and that they will die from pollution, just like the rest of his people. When Sonic asks the Kraken of what he means, the Kraken explains that he was once the king of this underground world, but then surface dwellers began polluting his world. As a result, almost his entire race has perished. In fact, he is the last survivor. Sally, however, explains to the Kraken that it is not them that are polluting the world, but Dr. Robotnik. Immediately after, another earthquake hits and two Snake Probes emerge from the wall and bind the Kraken. Soon after, a third Snake Probe emerges from the wall. Antoine wants to escape, but Sonic insists that they help the Kraken. Rotor tells Sonic that the Snake Probes are coming from the oil plaform on the surface. Sonic thus decides to run through the tunnel created by the Snake Probe. Once on the surface, Sonic begins to run inside the plaform. At the same time, Robotnik arrives in his hovercraft to admire his drilling platform. Noticing a dot on the monitors, Robotnik believes it to be a fly and tells Snively to get rid of it. Snively, however, informs Robotnik that the dot is actually Sonic. Getting mad, Robtonik sends the Swat-Bots on the drilling plaform after Sonic. As the Swat-Bots emerge from one door on the plaform, Sonic escapes to the other side, only to encounter more Swat-Bots coming out from the other door there. As such, Sonic runs up along the drilling platform's wall.

In the control center, Robotnik orders his Swat-Bot to activate all the Snake Probes. Before it can do that however, Sonic arrives and presses a button on the Swat-Bot's chair, causing the chair to drive the Swat-Bot out of the control room. Sonic then proceeds to activate the Snake Probe's emergency self-destruction feature. This makes the Snake Probes retract and self-destruct. Sonic then starts pressing all the buttons in the control center, singing the song that he previously practiced on using his electric guitar. With the drilling platform's system overloading, Sonic escapes from the plaform. The drilling palform subsequently collapses.

Sonic soon after returns to the Kraken, Sally, Rotor and Antoine in the underground lake. There, Rotor pours the green water in his canteen into the contaminated water. The water is then immediately purified. In gratitude, the Kraken gives Sonic a sack, the contents of which would help revive the Great Forest. Sonic thanks the Kraken and humorously tells him to let him know if he ever wants to go fishing. Back in the Great Forest, Sally pours some of the green water the Kraken had given them on the seedlings, causing them to grow very fast, much to the satisfaction of the heroes. Sonic then asks Rotor how it is like to be a hero. Putting an icepack on his head, Rotor admits it is exhausting and that he would prefer to be a handyman from here on out.


  • When Sally says "I hope so, Rotor.", Rotor's cap is gone.

Title in other languages

Language Title Translation
Czech Soník V Podzemí Sonic In The Underground
French Pollution Pollution
German Das Wunderwässerchen
Abenteuer in der Unterwelt
The Miracle Water
Adventure in the Underworld
Korean 환경 보호 운동 Environmental protection movement
Latin American Sub-Sonic Sub-Sonic
Russian ПодземныйСоник Underground Sonic
Spanish Sonic Sumergido Submerged Sonic
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