This page focuses on Sonic's Story in Sonic Adventure: Chaos Unleashed.

Here is the link to the other six stories:

Main article: Sonic Adventure: Chaos Unleashed/Tails' Story
Main article: Sonic Adventure: Chaos Unleashed/Knuckles' Story
Main article: Sonic Adventure: Chaos Unleashed/Amy's Story
Main article: Sonic Adventure: Chaos Unleashed/Big's Story
Main article: Sonic Adventure: Chaos Unleashed/Gamma's Story
Main article: Sonic Adventure: Chaos Unleashed/Super Sonic Story

Sonic's Story

In one night in Station Square, Sonic is running on the roof tops and runs up to a tall building, admiring the view. He enjoys the view until he sees the police rushing to city hall. Wondering what's happening, Sonic follows them. The police surround a mysterious water creature named Chaos. The monster had been wrecking cars and breaking windows, scaring the citizens in the process. The police open fire on Chaos, but their bullets simply bounced off of it and fall to the ground. Seeing that their weapons are useless, all personnel retreat. Sonic arrives and sets to battle the monster.

Boss: Chaos

After defeating Chaos, the creature escapes through a water drain, leaving Sonic staring at it, puzzled to know what is the monster and where did it come from. Overlooking these events from a rooftop is none other than the evil Dr. Eggman, who calls Chaos, the god of destruction.

Morning time came, and Sonic is relaxing by a pool at the Station Square hotel until he sees a plane spinning out of control in the sky. Sonic looks closely and realizes the plane's pilot is Tails! Sonic warns him that he's going to crash, but Tails couldn't hear him and the plane crashes into Emerald Coast. Sonic races off to rescue his little buddy.

Adventure Field: Station Square

Stage 1: Emerald Coast

Soon, Sonic rescues Tails. The two friends greet each other, and Sonic asks him what caused the plane to crash. Tails explains that the plane was a prototype and needs some bugs to iron out. Sonic tells him that he can borrow his Tornado bioplane. Tails thanks him for the offer, and reveals that his new plane is powered by a purple Chaos Emerald. Tails asks Sonic to follow with him to his workshop in the Mystic Ruins so that he can show him something he's been working on.

What Sonic and Tails didn't realize is that Orbot and Cubot, Eggman's quirky minions, overheard their conversation and inform Eggman that they are in possession of the Chaos Emerald. Eggman tells him to meet with him at the Mystic Ruins and he will confront the two in person.

Adventure Field: Station Square, Mystic Ruins

Sonic and Tails travel to the workshop, but Dr. Eggman, along with Orbot and Cubot, shows up and demands that Sonic and Tails hand over the Chaos Emerald or he will take it by force, and transforms his Eggmobile into the Egg Hornet.

Boss: Egg Hornet

After defeating the Egg Hornet, Sonic remarks that the battle wasn't that difficult. Suddenly, out of nowhere, Eggman steals the Chaos Emerald from Tails' hands, and reveals Chaos, the monster Sonic fought earlier. Eggman gives Chaos the Emerald and the monster absorbs it, gaining a line of bone on his right arm.

Eggman explains that every time he feeds Chaos with every Emerald, his strength increases and becomes bigger. And with all 7 Emeralds gathered, Chaos will become invincible and will destroy Station Square. After that's done, Eggman will build his utopia, Eggmanland, upon its ruins. Eggman, Orbot, Cubot, and Chaos disappear, leaving Sonic and Tails to decide to find the rest of the Chaos Emeralds before they do.

Adventure Field: Mystic Ruins

Stage 2: Windy Valley

Adventure Field: Mystic Ruins, Station Square

Stage 3: Casinopolis

After finding another Chaos Emerald, Sonic and Tails exit Casinopolis. Unfortunately, Eggman confronts them. He tries to shoot the two with one of his missiles; Sonic and Tails duck them, but on the process, they dropped the Emerald, allowing Eggman to take it.

The next morning, Sonic and Tails wake up and realize that Eggman has stolen the Chaos Emerald, but are still in possesion of the other one. The two then continue their search for the other Chaos Emeralds.

Adventure Field: Station Square

Along the way, Sonic and Tails meet Cream and her pet Chao, Cheese. Cream greets the two and shows them an ice stone key she found at the Mystic Ruins the other day as well as the wind stone key. Sonic and Tails figure that they can find a door to the key in the Mystic Ruins. They thank Cream and set off as Cream returns to meet with her mother.

Adventure Field: Station Square, Mystic Ruins

Stage 4: Ice Cap

Adventure Field: Mystic Ruins

After retrieving the Chaos Emerald, Sonic and Tails run into Knuckles. The two greet him, but Knuckles attemps to attack them. He accuses Sonic of stealing Master Emerald's shards, and the two beginning their fight.

Boss: Knuckles the Echidna

The fight ends with a tie as Sonic and Knuckles bump into each other, causing Sonic to drop the two Chaos Emeralds. Eggman, Orbot, and Cubot arrives and seizes the opportunity to take the Chaos Emeralds. Looking at a green Chaos Emerald Eggman was holding, Knuckles realizes that Eggman had tricked him, much to Sonic's displeasure. Eggman summons Chaos and gives the Emeralds to him, turning him into Chaos 4.

Boss: Chaos 4

After the battle, Eggman introduces the trio his flying aircraft the Egg Carrier and escapes with Orbot and Cubot inside. With Knuckles resuming to his unfinished business, Sonic and Tails chase after Eggman on the Tornado.

Adventure Field: Mystic Ruins

Sub-Game: Sky Chase I

During the stage, Eggman shoots out a laser beam from the Egg Carrier, damaging the Tornado's wing in the process. Sonic and Tails fall off, and are separated.

Sonic lands in Station Square, wondering what happened to Tails.

Adventure Field: Station Square

Sonic runs into Amy, who asks for his help to her protect a bird she named "Birdie". Amy concludes that they will tag along anyways. Sonic runs off, with Amy chasing him.

Adventure Field: Station Square

Sonic and Amy are confronted by Zero. Sonic starts to fight it, but Amy screams out and points out to him Twinkle Park where "cute couples get in free". Annoyed, Sonic goes in with her.

Stage 5: Twinkle Park

After clearing the stage, Sonic finds out that Amy has gone missing and seeks to find her.

Adventure Field: Station Square

Stage 6: Speed Highway

Adventure Field: Station Square

Sonic is still looking for Amy, but he finds out that Amy is kidnapped by Zero and both are heading to the Mystic Ruins. Sonic sets off to chase them. 

Adventure Field: Station Square

Sonic finds Zero with the captured Amy. He threatens the robot to release her. Out of nowhere, The Egg Carrier appears and Amy and Zero are taken to it. Knowing that he has no other choice, Sonic decides to chase them on foot. 

Adventure Field: Mystic Ruins

Stage 7: Red Mountain

After clearing the stage, Sonic watches the Egg Carrier flying away. Just then, Tails shows up with the Tornado II, powered by a Chaos Emerald. The two friends give in chase.

Sub-Game: Sky Chase II

After clearing the stage, Sonic and Tails are approaching the Egg Carrier, but to Sonic's shock, Tails informed him that there's no landing gear in the Tornado II's battle mode. Despite the uneasy landing, they were safe nonetheless. Sonic tells Tails that Amy has been kidnapped and the two set off to rescue her. Knowing that they have arrived, Eggman taunts them and orders Orbot to transform the Egg Carrier into a different shape, and challenges the two to enter the Sky Deck. Sonic declares that he'll show Eggman that he and Tails will get past his Sky Deck.

Adventure Field: The Egg Carrier

Stage 8: Sky Deck

After clearing the stage, Sonic and Tails manage to enter the interior of the Egg Carrier. Knowing that Amy was nowhere here, they decide to exit the interior to continue their search.

Adventure Field: The Egg Carrier

Outside of the rear section of the Egg Carrier, Sonic and Tails find Eggman and Amy. He tells them that they are too late and takes a Chaos Emerald from Birdie. Eggman then calls forth E-102 Gamma to destroy Sonic and Tails.

Boss: E-102 Gamma

After defeating Gamma, Sonic begins to give him a finishing blow, only for Amy to block his way. Sonic asks Amy to get out of the way, but she explains to him that Gamma helped her escape and pleaded him not to hurt him. Sonic relents. Suddenly, there was a rumbling on the Egg Carrier. Tails informs them that the Egg Carrier is losing altitude. Sonic tells Tails to take Amy to safety while he chases Eggman.

Adventure Field: The Egg Carrier

With the Egg Carrier transformed into its original shape, Sonic finds Eggman, Big, and Chaos who has already transformed into Chaos 6. He then notices that Big's pet, Froggy is trapped inside Chaos' body and offers to help Big to save him. Eggman laughs and tells Sonic that he has no chance against Chaos even if he's not yet reached its final form.

Boss: Chaos 6

After Chaos 6's defeat, Eggman yells at Sonic in frustration. Sonic taunts him that Chaos 6 is defeated, but his face fell when Chaos 6 appears again. As Eggman leaves the Egg Carrier, Knuckles arrives and tells Sonic that he'll fight Chaos 6 while he chases after Eggman. Sonic agrees and follows Eggman.

Sonic, who had mistimed his jump, lands in the jungles of the Mystic Ruins and expresses frustration that he couldn't catch Eggman. He sees a light heading inside an ancient temple. Sonic assumes that it wants to show him something and follows it.

Adventure Field: Mystic Ruins

Stage 9: Lost World

After clearing the stage, Sonic follows the light to a room full of murals. Designed on the middle mural is Chaos destroying the city. Suddenly, Sonic is taken back to 4,000 years of the past where the Master Emerald Shrine is engulfed in flames and everything is damaged. He goes to find out what's going on.

Adventure Field: Mystic Ruins (The Past)

Sonic examines the damage further and finds Tikal terrified of the damage that has been caused to the shrine and decides to do something before things will get worse. Before he can learn anything, Sonic is returned to the present, wondering if he was dreaming. Just then, Eggman passed by with his Eggmobile, heading towards his base. Sonic sets off chase, hoping to defeat him once and for all. Orbot

Adventure Field: Mystic Ruins

Stage 10: Final Egg

Sonic finds Eggman, Orbot, and Cubot inside the Egg Viper. Eggman revisits all of the times Sonic interfered in his plans and how he always defeats him (Displaying are flashbacks of the events of Sonic 1, Sonic CD, Sonic 2, and Sonic 3 & Knuckles where Sonic defeats Eggman); since Chaos is defeated, he declares that things are going to be different and he will be the one to settle the score with the blue blur once and for all.

Boss: Egg Viper

The cutscene takes in the Mystic Ruins where, Sonic watches Eggman flying away with his Eggmobile in critical damage and is yelling at Orbot and Cubot. Later, Sonic meets up with Tails, and the two give each other a fist bump and rest as the work is done. This leaves with a cliffhanger of Chaos wandering in the jungle in his blob form, indicating that the battle is far from over.

THE END?

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