In a battle, Sonic the Hedgehog destroys Doctor Eggman's Energy Amplifier, powered by the seven Chaos Emeralds. This causes an explosion, a result of a phenomenon known as Chaos Control, which sends Sonic; Eggman and his fortress; Rouge the Bat; Cream the Rabbit and her pet Chao Cheese; Miles "Tails" Prower and the biplane he flies, the Tornado 2 (Tornado); Amy Rose; and Knuckles the Echidna to Station Square, a city on Earth. The police try to catch Sonic by deploying the Speed Team, led by Formula One car driver Sam Speed, but he outruns the team and escapes; however, he falls off the road and into the pool of a mansion. Sonic, who cannot swim, is saved by Chris Thorndyke, a young boy who lives there.

Sonic meets Chris' inventor grandfather, Chuck. After finding that Cream and Cheese are being held at Area 99, a military research base, Chris and Chuck help Sonic bust them out, and they reunite with Tails and the Tornado. Meanwhile, Doctor Eggman, whose fortress has been sent to a deserted island, schemes to establish an "Eggman Empire" on Earth.

Doctor Eggman deploys his robot E-23 Missile Wrist in an attempt to take over Station Square, but Sonic defeats him with Knuckles and Amy's help. The police try to capture them, but they escape; Amy returns to the Thorndyke mansion with Sonic and co., while Knuckles leaves to be on his own.

The President and the government begin spying operations on Doctor Eggman, and install an agent, Mr. Stewart, as Chris' elementary school teacher to keep tabs on him. The heroes theorize that if they can gather the seven Chaos Emeralds again, they can send Sonic and the others back to their world. The green Chaos Emerald is discovered at a construction site; Eggman and Chris fight over it, and Chris successfully recovers the green Emerald.

Knuckles is anxious to return to his world so he can guard the Master Emerald. Doctor Eggman falsely tells Knuckles that Sonic intentionally caused Chaos Control and is undermining Eggman's efforts to go home so he can live out the rest of his life peacefully. Enraged, Knuckles challenges Sonic to a fight. Eggman uses the fight as a distraction to capture Chris, Amy, and Tails. When Knuckles realizes he fell for a ruse, he helps Sonic defeat Eggman.

Doctor Eggman sends E-51 Intelligente, a teacher robot, to indoctrinate Chris' class, but Sonic thwarts his plan. Chris' parents—Nelson, a wealthy company president, and Lindsey, a famous actress—return home after a long absence.

Nelson and Lindsey go back to work, with Chris and his mother both being unhappy about Chris' parents' absences. Cream misses her mother. Sam Speed is revealed to be Chris' uncle. The Thorndykes' maid and chef, Ella, and butler, Mr. Tanaka, learn about the animals.

Doctor Eggman uses a rocket ship, E-90 Super Sweeper, to suck up satellites for parts. Sonic and Tails use the Tornado to fly to it, but are unable to keep up. Tails and Chuck convert the Tornado into the more powerful X-Tornado, powered by the green Chaos Emerald, and the team destroys Super Sweeper.

While Chris attends the grand opening of "Hotel de Blanc" as a representative of the Thorndyke family, Amy, Tails, Cream, and Cheese visit the Thorndykes' private beach villa. Sonic stays behind due to his inability to swim and distaste for the ocean. Amy, who has a crush on Sonic, makes a special charm that supposedly improves swimming ability as a gift for him. Doctor Eggman destroys the Hotel de Blanc and builds a theme park in its place. Sonic comes to stop Eggman, but he is saved by Amy after Eggman uses Sonic's weakness against him. An Eggman robot breaks Amy's charm, causing her to enter a fit of rage; she is flung into the ocean, and Sonic reluctantly dives in to save her. When Amy comes to, she grieves the loss of the charm but vows to make another. Sonic is then seen looking out over the sea, holding a repaired charm.

As Tails cruises in the X-Tornado, the green Chaos Emerald draws him to Diamond Stadium, a baseball stadium. Its groundskeeper, Alfred Butler, tells Tails that Diamond Stadium will soon be demolished because its home team is moving to an indoor stadium. Alfred has also found the cyan Chaos Emerald at the stadium. Eggman challenges Sonic and co. to a baseball game against his robots for both Emeralds. As the two teams play, the stands fill with spectators; inspired, the team's manager, Elmer Johnson, offers to move Diamond Stadium's turf to the team's new stadium, which Alfred happily agrees to. Sonic's team ultimately defeats Eggman's, but he steals the cyan Emerald anyway and escapes.

The President seeks Sonic's help to attack Doctor Eggman's fortress. They set a trap for him under guise of a Chaos Emerald, but end up catching Rouge the Bat instead, who has become a serial jewel thief. In exchange for amnesty, the President gives Rouge a job as an agent instead; she accepts, reasoning that being an agent will give her information about the Chaos Emeralds, which she wants for herself. She and an agent named Topaz go on a mission to infiltrate Eggman's fortress. Despite distrust of Rouge, they gain information about the fortress and Rouge saves Topaz from Eggman's robot. Meanwhile, Chris introduces his friend Danny to Sonic and the others.

Chris, Tails, Amy, and Chris' friend Frances detect a Chaos Emerald underground in a cornfield. While they dig for it, Doctor Eggman arrives to take it for himself; the heroes try to defeat his wind-blowing robot, E-35 Funfun, by transforming the X-Tornado into the X-Cyclone, but they struggle. Mr. Stewart, who has been tailing Chris and co., calls the Thorndyke residence, and Sonic rushes to their aid. Meanwhile, the President sends Rouge and Topaz inside Eggman's fortress again while the navy and air force barrage it from outside, in the hopes of stopping him once and for all.

Sonic destroys Funfun, but Eggman escapes with the yellow Chaos Emerald. Sonic, Tails, Amy, Chris, and Frances fly to Doctor Eggman's fortress, where the attack is in progress. Knuckles also hitches a ride on an air force plane, and finds Rouge and Topaz. They plant an explosive charge to destroy the fortress, but get locked inside while the timer runs. Sonic takes the cyan and yellow Chaos Emeralds from Eggman's robot and uses their power to break out Rouge, Topaz, and Knuckles. The heroes escape and the charge detonates, demolishing Eggman's fortress. The people of Station Square, watching the attack on television, celebrate the victory as they cheer Sonic's name.

Since the public largely gives Sonic credit for defeating Doctor Eggman, the President's aide organizes a party for Sonic and the press, hoping to associate the two in the media so that the President can win reelection. Sonic does not attend the party with his friends; he promised Chris' physically disabled classmate Helen to take her to an island to see flowers, which her father is not able to do because he is too busy working to support her. The President's aide deploys the military to find Sonic and bring him to the party, and Sonic and Helen's excursion becomes an exciting chase as Sonic pushes her wheelchair. After escaping by stealing a helicopter, Sonic and Helen go to the President's party and Sonic shakes his hand, but the reporters are unable to take pictures because they are intensely drunk (in the English version, they are simply tired from the long wait). Later, as Helen tells the story of her first adventure to her parents, they commit to spending more time with her.

Chris and Ella take Tails, Amy, Cream, and Cheese shopping in Station Square since they are now publicly-known figures, but they find it difficult to do things without drawing attention. Meanwhile, at the wreckage of Doctor Eggman's fortress, an airship he calls the Egg Fort emerges and terrorizes the city. Sonic appears, but is unable to reach the Egg Fort. Chris' group escapes the city, aided by Mr. Stewart, Sam Speed, and Mr. Tanaka, and bring the X-Tornado to Sonic. Sonic destroys the Egg Fort and it falls into the ocean, but the heroes assume it will be back.

As thanks for their service to the country, the government issues Social Security numbers and passports to the animals, as well as a pilot's license and various other permits for Tails. Chris and the animals travel to the Sapphire Sea for a vacation, but detect a fourth Chaos Emerald under the water. When they go to a store to get scuba diving gear and a boat to look for the Emerald, they learn a legend about a sunken ship with treasure inside. As the heroes dive, they find the blue Emerald as part of the ship's sunken treasure. Meanwhile, as Doctor Eggman learns about Sonic's vacation, he emerges from the ocean to ruin it; Sonic defeats him with Sam Speed's help, but the sunken ship is buried under rocks during the battle. When they go to return the diving equipment, they tell the owner that the ship was buried, but he is simply glad that the legend was true, as it was his grandfather's boat.

One day, Knuckles befriends a fellow treasure hunter named Hawk. Some time later, Hawk calls Knuckles to "Oriental City", where he believe he has found a Chaos Emerald. Knuckles and Hawk dig up the red Emerald's hiding place in the subway, but they get into a fight with Doctor Eggman's robot, E-91 Lady Ninja, for it. During the battle, the Emerald is buried under a pile of heavy rock; Knuckles retrieves the "Shovel Claws" to dig it out again. As Knuckles and Hawk escape the city with the Emerald, they are pursued by Lady Ninja and Rouge. After destroying Lady Ninja, Knuckles leaves Hawk. As he floats away on a boat, the red Emerald gives Knuckles a cryptic vision of the Master Emerald.

Note: The episode's Japanese title is a reference to the 1972 Hong Kong martial arts film of the same name.

After a battle in the air, Sonic, Tails, Chris, and Doctor Eggman crash-land in Africa. Tails and Chris find a construction company building a dam in the middle of the savanna. To help the animals, they get the people of a nearby city to picket against the dam's construction, forcing it to close. Meanwhile, Sonic battles Eggman's ape robot, E-65 Gorru-Gaooh; Eggman and Gorru-Gaooh inadvertently destroy the construction site and thwart the construction manager's further schemes before Sonic defeats Eggman and the managers are arrested.

The heroes visit a castle to watch Lindsey film a movie. When a cameraman disturbs an hourglass-shaped stone from a pedestal, ghosts appear and kidnap several people, leaving only Chris and Amy. They discover an underground chamber under the pedestal, and venture down to where the people are being kept. The leader of the ghosts, King Boom Boo, mimics Sonic's voice, tricking Amy into placing the hourglass into a slot and strengthening him. Chris flips the hourglass, freeing the kidnapped people and allowing Sonic and Amy to defeat the ghosts; all the heroes escape, and they seal off the underground chamber.

• King Boom Boo is based on the same boss that Knuckles fought in Sonic Adventure 2.

The heroes go on vacation on a cruise ship. Sonic struggles to relax without an open space to run in, so Nelson sends a group of senior citizens to help him learn to slow down. Meanwhile, Doctor Eggman abandons the Egg Fort and debuts the Egg Fort II. He sends his robot courier, Bokkun, to announce it at the Thorndyke mansion, and he blows up a bomb in Ella's face. Eggman finds the cruise ship, but before Sonic can fight him, an enraged Ella arrives in the X-Tornado to get rid of him personally. Tails asks Sonic if he wants to leave the cruise early, but Sonic decides to stay and relax instead.

Sam Speed challenges Sonic to a race with a new car, but Sonic is not interested. The President's aide, intending to use the race as another publicity stunt for the President, convinces Doctor Eggman to persuade Sonic, so he sends a kissing robot that will kiss Sonic if he doesn't race, and Sonic finally agrees. Sonic and Sam have a very close race, but Sonic ultimately wins. The President is running late at a meeting, so the President's aide intends to take his place in the press photos so that he can become President himself; however, he receives a call notifying him that he has been fired from his position for conspiring with Eggman.

Chris, Danny, Frances, Mr. Stewart, and the animals camp with Mr. Tanaka near his Japanese hometown for summer break. After Cheese is swept away by a river current, the heroes discover a Chao colony in a secluded area. Meanwhile, on vacation, Doctor Eggman's mecha falls due to the soft terrain, dirtying the river. This endangers the Chao, who must live in clean water. After exploring the town and enjoying his fame, Sonic destroys Eggman's mecha and rescues the Chao habitat by running around the water and blowing the dirt out.

Nelson purchases a ring of the purple Chaos Emerald, intending to give it to Lindsey for their wedding anniversary. The heroes travel to "Filmdom City" to see Nelson present the ring to Lindsey, but the Emerald is also pursued by Rouge and Topaz and Doctor Eggman. Sonic, Knuckles, and Eggman fight across several film sets, but ultimately Eggman escapes with the Emerald. Despite the loss of the ring, the heroes celebrate the Thorndykes' anniversary.

After saving Amy from a Doctor Eggman robot, Sonic gets a circuit board from it lodged in his ear, forcing him to run without stopping. He runs to the badlands so as to not endanger the city. Over the next two days, Sonic's friends try various schemes to trap him and stop him from running, but they all fail. Eventually, they lead him back to where he fought the robot, and after saving Amy from it again, the board comes loose, allowing him to come to a stop.

Sonic and co. hold four Chaos Emeralds, and Knuckles and Doctor Eggman each have one. Chris is torn on whether he wants Sonic and friends to return to their world, or if he wants them to stay. Knuckles realizes they can't do Chaos Control if the Emeralds are separate, so he takes Chris to make a deal with Eggman. As part of the deal, Chris takes the Emeralds without Sonic knowing, and he and Knuckles give their Emeralds to Eggman. When his robot, E-77 Lucky, finds the final white Emerald, Eggman captures Chris and takes off in the Egg Fort II.

Sonic reaches the Egg Fort II and recovers the white Chaos Emerald from Lucky. The Egg Fort II turns into a large robot. Sonic loses badly in a fight against it, and it flings him into the sea. Chris breaks free from the bolts holding him to the wall in the control room and grabs the six Emeralds, intending to avert Chaos Control. Chris also falls into the sea; he is saved by Rouge, but the Emeralds fall into the water. There, the six Emeralds react with the one Sonic holds, transforming him into Super Sonic. After Super Sonic destroys the Egg Fort II, Chaos Control occurs and another burst of light appears. Chris cries that Sonic will leave, but when the light clears up, Sonic appears in front of Chris, showing they are still together.

• The original Japanese TV broadcast uses an insert song "Kotoba ni Dekinai" by OFF COURSE, while the home video release uses an instrumental of "The Shining Road".

Chaos Control did not send Sonic and friends back to their world, but instead brought more elements from Sonic's world to Earth, including the floating Angel Island where the Master Emerald resides. Six months later, Doctor Eggman has been quiet, secretly developing an E-100 Series of robots, including E-101 Beta, E-102 Gamma, E-103 Delta, and E-104 Epsilon on his new ship, the Egg Carrier. Big the Cat discovers the purple Chaos Emerald; his pet (non-anthropomorphic) frog, Froggy, swallows a blue liquid and steals the Emerald before running away. Big comes to Chris, Cream, and Cheese for assistance in finding him. During their search, they encounter the blue liquid, which forms into Chaos, a humanoid monster which gets stronger upon consuming Chaos Emeralds. Sonic arrives after a solo journey, and Knuckles comes looking for the whereabouts of the missing Master Emerald. Eggman appears and reveals his plan to use Chaos to take over the world. He feeds Chaos both the yellow and red Emeralds; Sonic and Knuckles are barely able to defeat him. Chaos escapes with Eggman.

• This episode begins an adaptation of the video game Sonic Adventure.

Sonic enlists Tails' help to find the Chaos Emeralds before Doctor Eggman. They discover the cyan Emerald, but Eggman arrives and steals it, as well as Tails' green one. He feeds them both to Chaos, but Sonic is able to defeat him. Meanwhile, Knuckles finds a shard of the shattered Master Emerald, which gives him a vision of an ancient echidna tribe in front of the Master Emerald; in it, a young girl, Tikal, pleads for her father, the tribal leader Pachacamac, to stop warring with other countries for their Chaos Emeralds, but he refuses. Amy, Cream, and Cheese meet a bird with a Chaos Emerald around her neck, which they name Lily, but Eggman's E-100 ZERO abducts Amy and Lily.

Big and Chris fish up the missing Froggy, but E-102 Gamma steals it and takes it to the Egg Carrier; the two sneak on board. Eggman takes Froggy, and dismisses the other three E-100s. He instructs Gamma to bring him Lily; however, when it sees the E-100s being disassembled and Amy pleads for Gamma to be kind, he frees Amy and Lily from their cell, allowing them to escape. Meanwhile, Knuckles finds more Master Emerald shards and brings them to Angel Island, although some shards are still missing. He sees another vision in which Tikal learns that the Master Emerald controls the seven Chaos Emeralds. Sonic and Tails meet up with Knuckles in the X-Tornado, and they make a crash landing on the Egg Carrier to rescue Amy and Lily.

On the ship, Doctor Eggman takes the blue Chaos Emerald from Lily. Sonic battles E-102 Gamma, but Amy forbids him to destroy it. Tails takes Amy and Lily back to the ground, and Amy vows to find Lily's family, who are still captured by Eggman. Meanwhile, Knuckles finds the remaining Master Emerald shards and sees a vision where the forest is on fire; Tikal tells Knuckles she failed to stop her father. Knuckles helps Sonic defeat Chaos, now with six Chaos Emeralds. Eggman tries to flee, but Sonic follows; he is dropped to the ground, where he finds an overgrown temple. Big and Chris rescue Froggy after Eggman takes his Emerald, and they and Knuckles, who retrieves the Chaos Emeralds, return to the ground; Knuckles goes to repair the Master Emerald, and Big and Froggy return home. Back in Station Square, Tails defuses an Eggman missile and learns to be confident without Sonic, earning cheers from the civilians.

Sonic finds and breaks into Eggman's underground base, Final Egg. At the time, Gamma sets his friends free everywhere, but then E-101 Beta appears and they end up fighting.

Chaos, who has been defeated, turns out to be alive. Reaching its Perfect form, Chaos goes berserk and terrorizes the city by running amok, refusing to listen to Eggman. At that moment, Sonic's body suddenly begins to glow.

• Flood Fight (a.k.a. The Scream of Perfect Chaos) is the last episode to use the plot of Sonic Adventure.

Eggman hacks into GUN's computer and learns that his own grandfather (Gerald Robotnik) is connected to GUN's important secret "Project Shadow." He then infiltrates Prison Island with Decoe and Bocoe in tow to obtain it.

• Project: Shadow (a.k.a. The Mystery Of Project Shadow) is a prequel to Sonic Adventure 2.

Sonic has been captured by GUN. Apparently, GUN believes that Sonic has sneaked into Prison Island to steal the secret of "Project Shadow." Sonic, having no idea what is going on, escapes from GUN's helicopter and is pursued.

Sonic is put in an isolation cell on Prison Island. Chris and Tanaka go on a swan boat to rescue Sonic, while Amy and Tails also go on the X-Tornado. Eggman, along with Shadow and Rouge, attempts to infiltrate Prison Island again to get the Chaos Emeralds.

Prison Island is blown up and Chris is caught in Shadow's Chaos Control, escaping the blast. He finds himself in the Space Colony ARK, floating in outer space.

In order to stop Eggman's ambition to destroy the Earth, Sonic and his friends take a rocket to the Space Colony ARK. Sonic infiltrates inside, but is caught and thrown out into space.

Sonic and Shadow decide to fight. However, the computer of the Space Colony ARK has gone out of control. If nothing is done, the ARK will collide with the Earth.

• Showdown In Space (a.k.a. Maria's Wish and Everyone's Wish) is the last episode to use the plot of Sonic Adventure 2.

Sonic and friends' world and the human world have merged. Vector, Espio, and Charmy show up and start wandering the streets, looking for Cream. Meanwhile, Eggman reforms and claims he will repair the destroyed moon himself.

• Defective Detectives (a.k.a. The Chaotix Detective Agency) aired 2 days before the release of Sonic Heroes in Japan.

Suddenly, Eggman's artificial moon covers the sun and the world is enveloped in darkness. The reformed Eggman proposes a sunlight supply service to the president, which is well received by the citizens, but it is a ruse by Eggman.

Citizens' criticism of Sonic grows as he begins to interfere with Eggman's sunlight supply service. Chris, unable to defend him confidently, goes to stop Sonic, but learns that sunlight has actually been blocked due to Eggman's ambitions.

Amy is supposed to have a date with Sonic, but he never shows up. Angry, she decides to go for a drive with Sam Speed, who happens to be there. There, however, she encounters one of Eggman's robots.

• A Date To Forget (a.k.a. Amy's Love Went Away) is a prequel to Sonic Battle.

While Eggman and his henchmen in prison are forced to work at an electronics factory, they plant mysterious chips in many of the products. The result is that home appliances all over the city now move on their own and attack people, causing mayhem.

Stewart has begun a search to catch Eggman, who has escaped from prison. However, Chris and his friends find him and decide to search together.

As part of the project to capture Eggman, the President proposes a martial arts tournament with a Chaos Emerald at stake. Sonic, Knuckles, Chris, and even Emerl are to participate.

It is time for the finals. However, Emerl, reacting to the Chaos Emerald, begins to run amok, and everyone challenges him to a battle to stop him.

• A Wild Win (a.k.a. Sonic Battle - Finale) is the last episode to use the plot of Sonic Battle.

Eggman claims that he will use his giant battleship to stimulate the "belly button of the world," where submarine volcanic chains run through, and destroy the planet. Sonic and his friends try to stop him.

• The episode's Japanese title is very similar to the Japanese title of the 1969 sci-fi film Latitude Zero and there are several homages to the movie throughout the episode itself.

Eggman escapes into the crater of a volcanic island in his Egg Giant-Makan. Sonic and his friends follow him through the crater to the underground world, where they encounter giant monsters.

• The episode's Japanese title is very similar to the Japanese title of the 1965 sci-fi kaiju film Frankenstein Conquers the World and there are several homages to the movie throughout the episode itself.

According to the government, when Sonic and his friends are in the human world, a phenomenon called "Time Stagnation" begins to occur, and "time" becomes abnormal, causing the world to go crazy. The governors then propose to return Sonic to his own world, but Chris is reluctant.

• The episode's Japanese title is similar to the title of the 1951 sci-fi film The Day the Earth Stood Still.

In order to return Sonic and his friends to their own world, Tails and Chuck rush to develop the device. At that time, GUN troopers suddenly begin attacking Dr. Eggman's base. This is not the President's intent.

Just as Sonic is about to return to his world, Chris runs away with him. The two of them begin their escape.

Sonic returns to his original world. Chris looks up at the moon as he reflects on his memories of him.

• The original TV broadcast uses insert songs "Natsu no Hi" and "Midori no Hibi" by OFF COURSE, while home video releases use "Hikaru Michi" and "Event: The Last Scene" from Sonic Adventure 2.
• This was intended to be the series finale before it was renewed for a third and final season.

A new powerful enemy called a "Metarex" has appeared on Sonic's planet. Sonic struggles against them and its leader, Dark Oak, and the seven Chaos Emeralds are scattered, and the Planet Egg, the source of life on the planet, is stolen. At that time, 18-year-old Chris comes to the Planet Egg, warping in a portal he has built himself. But for some reason, he is now 12 years old.

It seems that Cosmo has come to this planet in search of Sonic in order to recover the Planet Eggs of various planets from the Metarex. Hearing this, Sonic and his friends decide to leave for space. However, while the spaceship is under construction, a Metarex soldier attacks again. There, Sonic and his partners use the main cannon "Sonic Driver," which uses Sonic as a cannonball, to intercept Metarex Spike.

The Blue Typhoon, the spaceship on which Sonic and his friends boarded, arrives at Hydo, a planet that has become a water planet after being robbed of its Planet Egg. Chris and Sonic board the landing craft, but Sonic is kidnapped by the Metarex. Chris attempts to save Sonic somehow.

While the people of Planet Hydo are thankful after the defeat of the Metarex, Eggman tries to trick Knuckles into getting the Chaos Emerald. Just then, a frog-shaped Metarex appears and swallows the Chaos Emerald!

After arriving at Breezer, a blizzard planet, Sonic and his friends search for the Chaos Emeralds and arrive at the "Ice Palace" where the Metarex soldiers are located. They are apparently doing some kind of research there.

Sonic and his friends arrive at a certain jungle planet and defeat the Metarex's attack with Sonic Driver, but Sonic is sent somewhere with the force of the attack. Amy, Cream, and Cosmo are looking for Sonic, but then Metarex King Ape appears.

The Chaotix Detectives receive a request from Cream's mother. Various items have been sent from Chris' world via the portal from episode 53, and she wants them to be delivered to the Blue Typhoon. The Chaotix arrive by spaceship, but instead of being greeted by Chris and his friends, they are attacked!

The Blue Typhoon arrives at Hobidon, already a dead planet. There they find the wreckage and ruins of a colony, and Sonic and his friends go to the ruins in search of the Chaos Emeralds. But the ruins are the transformable Metarex Deserd itself. Sonic is in desperate straits. Then, to his surprise, Shadow appears.

Metarex Hellship, which once attacked Cosmo's immigrant ship, attacks the Crimson Egg. Its next target is the Blue Typhoon, on which Sonic and his friends ride. Sonic and his friends are forced to fight against this threat that has put even Shadow in a tight spot.

Tails and Cosmo, who had been separated from Sonic and his friends on the planet Alabasta, find a facility in a cave. There, copies of the Chaos Emeralds are being made by Metarex. Tails and Cosmo attempt to escape from the pursuit of Metarex Viper.

The two remaining Chaos Emeralds (Blue and Green) are inside the Metarex's fortress. When Sonic and Eggman learn of this, they team up with each other and attempt to break into the fortress. Then, they discover the two Chaos Emeralds and a Planet Egg.

Waiting for Sonic and his friends are soldiers of a Metarex army led by Dark Oak. Sonic and his friends are surrounded by the Metarex army around the fortress. It was all a trap. Sonic tries to escape, but he is confronted by Shadow over the Chaos Emeralds.

Rare visitors appear on the Blue Typhoon. They are the three members of the Chaotix Detectives. When Vector sees Tails and Cosmo chatting amiably, he is convinced that Tails is in love with Cosmo. In order to encourage Tails, who according to Vector is a late bloomer, Vector devises an unusual plan.

At last, the Blue Typhoon enters the galactic corridor. The interior of the corridor is a mysterious tunnel-like space, and it is blocked by cosmic dust that has blown in like the roots of a plant, preventing progress. The Blue Typhoon, stuck in the corridor, is attacked by Yellow Zelkova, the most powerful of the four Metarex bosses.

There is a massive Chaos Emerald signature from an asteroid. The Blue Typhoon heads there and found an old factory. Inside is a Chaos Emerald production plant. Then Black Narcissus, one of the four Metarex bosses, appears.

Molly, a young girl from the planet "Cascade," is fighting the Metarex to restore the planet. She becomes interested in Shadow, who is as strong as the legendary hero "Black Wind" himself. Shadow, Rouge, and Molly then decide to follow the signature of a Chaos Emerald to the mining site of Cascade.

• This is the second and final episode where Sonic and his friends aren't present, the first being "The Adventures of Knuckles and Hawk", and the only episode of Season 3 without Cosmo.

The Blue Typhoon, with Chris aboard, encounters the three Marmolims, Momo, Lue, and Lylem, who have a Chaos Emerald. Sonic and his team are then forced to return their ship to their home planet in exchange for the Chaos Emerald.

Sonic rescues a mysterious spaceship being chased by the Metarex, but the pilot of the spaceship is Decoe. At that moment, the Metarex's fleet warps out. To everyone's surprise, the Metarex and Eggman have teamed up.

The Chaotix Detectives run a café on a planet in the Metarex space. Today, a new customer visits the café. This time, however, it is Eggman, who has just been appointed as part of the four Metarex bosses.

Chased by the Metarex, the Blue Typhoon crash-lands on the planet Thunderbolt after a surprise attack by Yellow Zelkova. Yellow Zelkova is impervious to all attacks. In the fierce battle, Chris and Sonic are sent flying far away.

There is an intruder on the Blue Typhoon. It is Shadow, who is after Cosmo's life. Tails desperately escapes with Cosmo, but Shadow hunts them down, which means Cosmo is in danger.

Sonic and his friends learn that Cosmo has been used by Dark Oak as a "living spy tool" that transmits what she sees and hears. Sonic and his friends are shocked, but when Cosmo tries to leave, they hold her back and vow to fight with her.

The Blue Typhoon takes off from the planet Green Gate and heads for coordinates 000 000. There is the planet Aquarius, which requires Chaos Emeralds and a giant Planet Egg. The final battle with the Metarex armada is about to begin.

Chris and his team bet on the Master Emerald for a comeback. They are going to use the Sonic Driver mechanism to strike the Master Emerald's energy into the Chaos Emeralds. Shadow and the Chaotix join in on the task, pushing back the Final Mova's attack with all their might. In the midst of the battle, Eggman tells Chris a shocking revelation.

The Final Mova becomes a giant nut. As if in answer to Cosmo's prayer, the Chaos Emeralds once again revive their power, and the golden Super Sonic and Super Shadow stand side by side. The onslaught of the two brake through the nut's outer contour, finally causing it to explode into pieces, but it is not the end.

The battle is over. Chris, who has given up on returning to Earth because there is no hope of restoring the Master Emerald, receives an envelope from Eggman. Inside is a ticket labeled "one-way ticket to Earth."

• This is the series finale.