One whole year has passed after defeating Barodius and the Twelve Orders, Dan, Marucho and Shun have managed to rebuild Bakugan Interspace and expand it. The episode begins, with Dan battling two Subterra and Darkus brawlers in Interspace with Marucho and Shun observing the battle. Marucho's new Guardian Bakugan, Aquos Trister, complains about not being able to battle after leaving Gundalia to team up with him. Shun's new partner, Ventus Taylean, tries to tell Trister to be patient but the two end up squabbling. Meanwhile, Dan and Drago are about to finish off their opponents with Dragon Strength but Drago has a vision of a strange Bakugan that makes him miss. But after attacking them once again, he finishes them off with a few blows. After the battle, the Brawlers observe two rival teams battling, Team Anubias and Team Sellon. Ever since they appeared in Interspace, they have become among the top ranked battlers, just below Dan and Drago. Suddenly Team Anubias appears and starts trash talking about the Brawlers, almost to the point of battling each other. However their rivalry is interrupted by a sleazy dealer named Dylan who tries to get them to buy his stuff and cause both teams to leave.

Sometime after Dan's battle with Ben from Team Anubias, Marucho and Shun talk to Dan about having Drago sit out for a while. Dan, however, disagrees and says he will get Drago's powers under control, but secretly, he's extremely nervous about the amount of power Drago unleashed and decides to go and train to get Drago's powers under control. Meanwhile, Marucho decides to have a battle to make up for Dan having to sit out, so he fights against Jack of Team Aubias. He and Trister struggle to win against Jack and his Guardian Bakugan, Aquos Krakenoid. Meanwhile, Dan and Drago found an abandoned arena to use as a training ground, but when Drago is training, a mysterious Mechtogan who calls himself Zenthon appears and wreaks havoc on the arena. Dan and Drago try to defeat it, but it blocks Drago's attacks and eventually teleports away.

Shun and Marucho discover that Dan and Drago are training secretly, and that Drago spawned Zenthon. They then fight alongside Dan against Zenthon and none of their attacks are strong enough to defeat Zenthon's shield. The next day Sellon and Dan have a match but Shun decides to join in to help keep Drago from losing control of his new powers again.

Some tension between the Brawlers rises, when Shun suggests to Dan that he should take a break from battling as to avoid another one of Drago's power loss disasters. However, Dan interprets this as Shun mistrusting him and they argue. Shun is later confronted by Sellon, who still wants him on her team and suggests that he give Dan some tough love.

Dan and Drago have disappeared and all sorts of negative rumors are spreading throughout Interspace. Team Anubias is dominating the battlefield, now that Anubias himself is number one in the rankings. Shun and Marucho arrive in Interspace and discover that brawlers are now using BakuNano, equipment much like Battle Gear that amplifies a Bakugan's destructive powers. When they question Dylan, they discover that the upgrade for the BakuNano just appeared out of nowhere. Sellon has another talk with Shun and suggests that he take the position of leader of the Brawlers and put an end to the BakuNanos since Dan and Drago are gone. Shun at first refuses.

Dan and Drago finally arrive in New Vestroia, to train in an attempt to control Drago's new powers. In Drago's secret training area, Dan and Drago find Aquos Amazon, Preyas student and Preyas himself asking if Marucho is with him in which Dan replies no. Amazon, having heard all about Drago from Preyas, wishes to battle with Drago. However, Dan and Drago are unsure because they may lose control of their powers again. Dan determines that each time Drago has lost control it has been in Bakugan Interspace, a virtual world and the result may be different in the real world. While Drago and Amazon begin battling, Mag Mel and Razenoid begin feeling Drago's immense power, deducing that he is battling in the real world. During the battle, Dan and Drago suddenly have another vision of Mag Mel and Razenoid and they pass out with one last fireball. Preyas and Amazon leave while Dan and Drago rest.

Drago is seen training by himself for some reason. Then a flashback which shows Drago wishing to train on his own and away from Dan but he doesn't want Drago to train by himself but Drago says that he's no good to anyone and he flies away. Mag Mel is then seen talking to Anubias about the whereabouts of Dan and Drago and it would never occur to him that they were at New Vestroia, the home of all Bakugan. Mag Mel then gives Anubias a Chaos Bakugan called Darkus Iron Dragonoid and a new Mechtogan called Venexus. Mag Mel then tells Anubias to go to New Vestroia and to find Dan and Drago. Anubias then goes back to Bakugan Interspace and transforms into his Gundalian form. After that, he then goes to New Vestroia. Just as Anubias arrives to New Vestroia, he says that he is a messager and he says skip the introductions and to battle. Anubias first summons Darkus Iron Dragonoid and attacks Preyas and Drago with Ollan Terror attack. When Drago gets hit by the attack, Preyas steps in to defend him. While on Earth, Marucho and Shun are at the place where they were waiting for Dan in episode 6, talking about Dan.

Shun has been battling far more frequently since taking the position of leader of the Brawlers, and it is starting to take its toll on him. However, he is more determined than ever to put a stop to the chaotic battling when Mechtogans are allowed in battles and Shun decides to enter the Battle Royale to stop them. Things get tough when he goes up against Robin from Team Anubias and Soon from Team Sellon, who each uses Bolcanon and Krowl, each equipped with their BakuNanos, Hyper Pulsor and Slicerix. Shun and Taylean fight them but start losing. Shun and Taylean fight on. However, Taylean spawns a Mechtogan called Silent Strike, making things even more complicated. Shun tries his best to defeat it to no avail, and Silent Strike defeats both Bolcanon and Krowl. Shun is then rescued by Rafe and Paige with their Bakugan, Boulderon and Wolfurio.

Dan and Drago are trying to get full control of Zenthon, but fail. Then they attempt to fly up a cliff, but the strong wind pushes them down. Drago tells Dan that they are falling out of sync, but then they are paid a visit by their old friend Wavern as a spirit-voice who helps them. She tells them they have to help the Brawlers and get back in sync. Also, Paige and Rafe talk about the Brawlers as they were sent to be their students. Rafe says that he wanted to be like them after watching them battle against the Gundalian forces but realizes that they need to help them. Paige still doubts them. Meanwhile, Marucho is confronted by his father and must decide how to save Bakugan Interspace from further destruction. Marucho's father tells him to quit the Brawlers but after a talk from Trister, Marucho decides not to quit.

The episode starts at a cave in New Vestroia, with Wavern telling Dan and Drago that the mystery to the entity in their nightmares will be solved in the cave. Then, Dan and Drago enter the cave. In Bakugan Interspace, there is a Capture the Flag competition in the Dungeon arena. Marucho tries to convince Paige and Rafe to try to not battle as much in the competition, but they take that as an insult and they leave angrily. Soon, Shun comes and tells Marucho that the only way to stop the chaos is to battle. Elsewhere, Sellon is seen contacting Mag Mel and informing him about the Capture the Flag challenge and he thinks that the Chaos Energy produced will be massive and he will be able to break out of his prison. Before the competition, Team Anubias meet up. Anubias gives Bolcanon to Robin, Krakenoid to Jack and Horridian to Ben. Anubias then states that he will not be participating in the competition. At the beginning of the competition, a brawler enters but is quickly defeated by a large group of brawlers. Then, Shun arrives with Taylean and defeats them. Meanwhile, Rafe and Paige are doing well until Ben comes with Horridian. Rafe and Ben use their BakuNano and attack each other. Paige joins in but then a beam from Hyper Pulsor comes and attacks them. Jack and Robin arrive but Marucho jumps in with Tristar and disappear in a giant wave with Paige and Rafe. Meanwhile, Dylan begins to wonder who will win since the participants are strong and even in terms of strength. Then, Shun arrives in another location and is attacked by Soon and Chris. They begin to insult Shun (Chris calls him an 'emo twerp') and they use their Bakugan and BakuNano to battle Shun. Down in the sewers, Rafe and Paige complain that they didn't need Marucho's help. He tries to explain them that pure strength will not always lead to success.The two disagree but then they are ambushed by Jack. They begin to run but Marucho faints. Tristar explains that Marucho tried to plan the safest route with the least battles for 2 days and that tired him out, much to Rafe and Paige surprise, who underestimate Marucho's skills. Then, when they get closer to the flag, Ben and Robin are there. Jack then comes from behind and they all attack Tristar at once. However, Marucho uses an ability which acts as if Tristar wasn't there which leads the attacks to each other and Team Anubias loses. Also, Shun wins his battle against Soon and Chris. Marucho arrives at the temple, where the flag is at the top. There, Marucho sees Sellon who uses her BakuNano. Using her BakuNano, she manages to defeat Tristar but only before she finds out it was a distraction. Rafe with Wolfurio and Paige with Boulderon come out. As Boulderon runs up the temple, Sellon unleashes her Mechtogan, Braxion. Rafe succeeds in stalling for time as Paige gets the flag and the win goes to the Battle Brawlers. Then Marucho reveals his plan: He knew Shun would attract many Brawlers so there would be fewer people to brawl.

In the Cafe in Bakugan Interspace, Shun is trying to relax a little. Marucho then arrives, and tries to tell Shun that he is battling way too much and suggests a break on Earth. Shun gets angry, and says he doesn't need a break. Marucho then suggests battling him but Shun just leaves. Back on New Vestroia, Dan and Drago were talking about Code Eve. Wavern then asks who Code Eve is and they explain who she is. Wavern suggests looking through their memories. The first thing they see is when they first saw the Sacred Orb on Neathia. Then they are brought to the battle against Dharak Colossus and with Linehalt using his Forbidden Powers. After, they are brought to the final battle between Dharak and Drago. Finally, they are at the point where they are given the powers. They finally remember when Drago evolved. The feeling was the same as Drago losing control. They are brought back to New Vestroia. In Bakugan Interspace, Shun is in a championship battle and defeated a brawler with Cyclone Percival. Rafe and Paige talk about how Shun battles and how they are bad. He advances to the semi-finals to battle Anubias.

In Bakugan Interspace, Rafe and Paige win a battle, and the rank for the Battle Brawlers is going back up. With their new ranking, they will face of with Team Anubias in a 2 vs 2 match. Marucho vows to defeat them to get rid of the violence which leads to flashbacks of Bakugan using BakuNano. Meanwhile, on New Vestroia, Dan and Drago are training and they both think that they are in sync. Drago says that he wants to try a round with Zenthon. Drago then tries to summon Zenthon, however, during the process, Dan sees a violent vision of Razenoid commanding a whole bunch of Chaos Bakugan to attack Bakugan Interspace. Then, Razenoid summons a portal which leads to Bayview and attacks with a powerful attack. Dan is then about to faint but Drago catches him just on time. Afterwards, Sellon suddenly arrives. The matchups for the battles against the Battle Brawlers and Team Anubias are Marucho and Shun vs Anubias and Robin and Rafe and Paige vs Jack and Ben. They only show the battle between Marucho and Shun vs Anubias and Robin. Anubias uses Horridian while Robin uses Bolcanon. While in New Vestroia, Sellon reveals she is working for Mag Mel but she doesn't reveal her identity. She also says that the guy from before, Anubias, was also a servant but does not reveal his identity either and Dan was shocked. Sellon then commences the battle, summoning one Haos, one Ventus and one Subterra Iron Dragonoid while Dan uses Titanium Dragonoid.They are all quickly defeated by Titanium Dragonoid's Dragon Force Striker and Sellon said that was incredible. Then, Sellon summons six different attributed Flash Ingrams which all have BakuNano Shoxrox. Later, when Dan says that the only way to defeat all the six Flash Ingrams is to use Dragon Force Striker, Sellon's Haos Flash Ingram nullifies all Drago's abilities so Dan says if they can't use abilities, they have to summon Zenthon. They then focus to try to summon Zenthon and they are successful. The six Flash Ingrams then attack Zenthon with the BakuNano's but Zenthon retaliates by defeating five of the Flash Ingrams and Drago defeats one of them barehanded. Zenthon then speaks and thanks Dan and Drago for creating him and letting him do his job. Sellon then gets angry and summons three Mechtogan: Deezall, Rockfist and Miserak. Meanwhile, The battle begins in Bakugan Interspace as Anubias uses Horridian's BakuNano, Aeroblaze and Robin uses Bolcanon's BakuNano, Hyper Pulsor. During the battle between Dan and Sellon, Deezal, Rockfist and Miserak attack Zenthon brutally. Mag Mel is then seen getting massive amounts of Chaos Energy. Later when Miserak, Deezal and Rockfist activate their lasers, Dan is thrown back and sees a vision of Shun and Marucho vs Anubias and Robin. Zenthon then get attacked by Rockfist and Deezal when Zenthon is down. When Zenthon is down, Drago says that they're going to pay for that but Dan says to Drago, we have to stay in sync. They then convince Zenthon to get up and they then become all synchronized with each other. The bond between Dan, Titanium Dragonoid and Zenthon is used to summon a Mechtogan Titan called Zenthon Titan. Zenthon Titan then defeats Miserak, Deezal and Rockfist with ease and then Sellon tells Dan and Drago that they can keep their Gate and Key.

Before the episode begins with the Battle Brawlers going through a Dimension Portal, to get to Gundalia, Dan goes with the other Brawlers because this fight involves him too. Once they arrive, they arrive at the city lines and see a desolate land which used to have homes. Later, two Gundalian guards confront them. Marucho says they are from Earth and they are the Battle Brawlers, Paige says that she is a Gundalian and Rafe says that he is a Castle Knight, but the guards don't believe them. Then, Ren arrives and says they are his friends. They find out he is now the leader of the Gundalian Forces. Ren then brings them to a secret hideout. When they arrive there, they receive a message from Nurzak, who has become the first Prime Minister of Gundalia. He welcomes the Brawlers and he is happy to see them back. Then he asks if Paige has been a good student and she concurs, which delights him. Then, Nurzak explain how a castle had emerged from underground out of nowhere, and an evil person called Mag Mel, with his brutish Bakugan, Razenoid, started it all. Then, Fabia Sheen appears on the screen in her Human Form and the Brawlers seem happy to see her once again. Rafe bows down as he reveals to Dan Kuso and the brawlers that she became the Queen while the former Queen (Serena Sheen), became the Ambassador of Gundalia and Neathia, surprising the Brawlers. Nurzak then says that he doesn't know why they came and attacked Gundalia so they had to fight and Queen Fabia said that the Castle Knights are coming to help the Gundalians in their fight against Mag Mel and Razenoid. Prime Minister Nurzak and Queen Fabia then leave. Ren then tells them that Chaos Bakugan are probably going to the center of Gundalia, where the Royal Palace is. Everyone then agrees with Ren but then Dan wants to help because he has a connection with Mag Mel and Razenoid however, Marucho tries to get Dan to sit this one out because of what happened before, and they end up arguing. Then, Ren asks if he should know anything about them fighting but they don't say that it's nothing. Later, Ren shows the Brawlers a map of the city lines but Dan feels a vision who shows Mag Mel with Razenoid and the army of Chaos Bakugan going North through a place called Dalia's Valley. Dan then says that Mag Mel and Razenoid are going North through Dalia's Valley. Ren knows that the Valley and it goes straight to the Royale Palace. Ren then asks Dan how he knows this and reveals to Ren and the Gundalian Soldiers that he is linked with Mag Mel and Razenoid. The Gundalian Soldiers don't trust Dan because he has a link with Mag Mel but Dan says that he can be trusted and Ren assures with a little bit of doubt. Marucho then devises and prepares a plan for an ambush. At the valley, the group waits for Mag Mel to arrive and Dan experiences some pain in his head.

Dan With the war turning on the Chaos Bakugan, Linehalt, Aranaut, and the other Bakugan are trying to defend against them. While that is happening, Nurzak and Fabia talk about the War between Mag Mel and Gundalia. Nurzak speaks up and says that their next target will be Neathia if they are able to take Gundalia down. Fabia ensures him that the Battle Brawlers will definitely succeed because the Sacred Orb chose them. After the fall, Rafe and Dan get separated from Shun, Marucho and Paige. The Chaos Bakugan come after them and Rafe doesn't know what to do, wishing that Marucho and Shun were there to help them. Dan then tells Rafe that he will handle it and tells Drago to use Dragon Blazer on the roof and rocks tumble down which trap the Chaos Bakugan. Rafe is then amazed about what Dan and Drago just did and asks how he knew that. Dan says that he has learnt some things over the past few years. Dan then decides to go after Mag Mel and Razenoid. Rafe is suggesting that he should follow Dan, but Dan rejects the idea. Rafe then get mad and Dan explains everything to Rafe including the Gate and Key they have. Rafe then asks what is the Gate and Key and Drago say that their not really sure themselves. In the end, Dan becomes convinced and decides to trust his friends. He also realizes that they were trying to help him. Dan then tells Rafe to go to find the other Brawlers so they can help him while Dan goes after Mag Mel himself. Meanwhile, the rest of the team is having trouble during the battle against the Chaos Bakugan and Marucho wishes that Dan was here. Rafe then arrives and uses a BakuLaunch to throw Wolfurio which he is able to defeat most of them. Taylean then defeats the rest with Slash Rise Thunder. Rafe then says that Dan went to look for Mag Mel and the Brawlers say that he just mad because Marucho is now the Leader of the Battle Brawlers. Rafe then says it is more than that and he truly cares for the Brawlers.

During the rain in Bakugan Interspace, there is a shadow of a weakened Sellon hobbling. There is also a flashback of when Mag Mel created her and Anubias. Spyron then comes to hunt her down to bring her back to Mag Mel but is luckily saved by Chris and Soon. Meanwhile, Marucho is still trying to repair the access point but Rafe alerts them of Chris and Soon arriving with Sellon. Soon and Chris explain what happened but the Brawlers say that she can't be trusted and they begin to argue with them. Shun arrives to harshly say to ditch her but then, she suddenly turns into her true form to attack a hidden Pyrus/Darkus Flash Ingram. Shun then battles it and Sellon gives a tip to attack the horn. Shun manages to destroy it and Sellon reveals that she doesn't want to leave because of her inspiration coming from her teammates.

Then, Marucho's BakuColar shows that there is an army of Chaos Bakugan coming with Braxion, Miserak and Rockfist. Dan, Rafe and Paige head out first while Shun and Marucho stay behind to find more information about Mag Mel. When Dan arrives he summons Zenthon which quickly defeats a lot of Chaos Bakugan and Drago defeats Rockfist with no trouble at all. However, Rafe and Paige are having a little trouble with the Chaos Bakugan. Marucho reminds them to attack their horn and they are then successful. Shun, still distrustful, is keeping a close eye on Sellon through a security camera just in case she does anything evil. Zenthon and Drago have defeated every Chaos Bakugan and Mechtogan except Braxion but reinforcements come to attack the battlers who are hiding. Shun then heads there to help them while Sellon asks Soon and Chris for a favor. During the battle, Dan gets a transmission from Marucho who says Sellon has a message. Sellon says that she needs to tell Dan something really important about the link between him and Mag Mel in person. As Dan is heading there, Shun summons Silent Strike to help. Dan then arrives to see Sellon lying on the ground. As he comes to help, she reveals that she tricked them and turns into her true form. She knocks Dan and Drago to the wall and takes the Key! Suddenly, Shun arrives and the pursuing battle begins. Sellon says they are alike but that makes Shun very angry and Taylean then defeats Spyron, Vertexx and Krowl. Sellon then flies away and tries teleports back to Mag Mel. Shun tries to stop her but is held back by Chris and Soon. Sellon thanks them and starts revealing Mag Mel's true plan, which ends up having Soon and Chris betrayed once again. She goes through a Dimensional Gate and the Bakugan fall back. Mag Mel is pleased that he finally has the key. He then absorbs Sellon's energy despite her success and her pleading. Dan is angry that he had been duped as Anubias looks from far off on building, then jumps off.

Haos Aerogan continues his training in New Vestroia to jump high set by his mistress/master. However he yearns for more battling experience after continuously jumping higher since the beginning of training. Aerogan then sneaks off to Earth to find a potential battling partner so he can fight other Bakugan. Aerogan transports to Bakugan City but gets a less-than-welcome greeting from each of the Bakugan requesting for a battle. Aerogan is repeatedly buffeted and pinballed until he ends up making a soft landing into Runo's drink, who was relaxing in the park. Runo cleans Aerogan up and explains to him the current climate and how the Battle Brawlers are watching for any signs of Wiseman's movements. Aerogan is elated to hear that Runo is part of the Brawlers and is adamant to be her partner, despite Runo having given up brawling. However she does bring him back to the Brawlers' headquarters where the other Bakugan cites Aerogan's enthusiasm to join them but lacks the battling experience and its purpose. Dan leaves saying that Aerogan is now Runo's problem, much to her annoyance. Mira's analysis confirms Aerogan's high jumping prowess but Aerogan asks to train somewhere with Runo so she takes him to a place where Shun goes for his ninja training. Runo repeats her statement that she is not Aerogan's battling partner and that she and her former Guardian Bakugan, Tigrerra gave up battling on the front lines to protect their friends and family. As Aerogan begins jumping, Wiseman is revealed to have eavesdropped on the conversation, surprised that Runo was once a Battle Brawler.

The Brawlers are sent to the Doom Dimension. Gunz Lazar and the Nonets are angry with Mechtavius Destroyer for robbing them of their revenge against Drago. Mechtavius Destroyer then tells the Nonets that he will destroy them and absorb their powers for himself, and that they will become a part of him. He then takes them all down with ease. Gunz then grabs the Nonets and runs off with them into the woods. Meanwhile, in the Doom Dimension, the Brawlers are clueless as to how to escape. Reptak then tells the Brawlers he is sure that Red Wiseman was the real Gunz. Dan later suggests that Drago try to teleport out of the Doom Dimension like before. Drago tries but fails, leaving the Brawlers realizing that they are in serious trouble. Gunz and the Nonets are plotting to fight Mechtavius Destroyer and take him down for good. Stronk suggests that he and Spatterix combine but Spatterix does not want to as he does not like to combine with Stronk. They leave the woods and find Mechtavius Destroyer who fires at them. Gunz throws out Spatterix who tries to hold back the blast but is not powerful enough. Gunz then throws out Stronk who combines with Spatterix to form Scorptak and proceeds to attack Mechtavius Destroyer. Gunz then throws out Betadron, Kodokor, and Mutabrid who plan on combining as well but are shot down by Mechtavius Destroyer before they have the chance. The Darkus Nonets prepare to combine a second time but Mutabrid is shot point-blank by Mechtavius Destroyer and is weakened greatly. Despite this, he still insists on combining but he is once again shot by Mechtavius Destroyer. Mutabrid then apologizes to his brothers and dies and is then absorbed by Mechtavius Destroyer. Gunz then throws out Tremblar. Enraged, the Nonets attack Mechtavius Destroyer all at once and momentarily destroys his shield. However, before they can attack again, the shield forms back.