The Winx hold a benefit concert to raise money to clean up from Earth's oil. Tritannus absorbs the spill's pollution, transforming him into a monster. He and the Trix escape the prison, setting off to rule the magic dimension.
The Winx turn a concert into an oil spill clean-up benefit, but Tritannus escapes from jail, absorbs the oil's pollution and turns into a monster.
The Winx hold a benefit concert to clean up the oil spill. After their song, Aisha finally receives a phone call from Tressa. The mermaid princess informs her cousin that Tritannus attacked Nereus and his father sentenced him to do time in the Prisons of Andros.
Meanwhile, some of the toxic waste from the oil spill enters through the Earth's ocean gate. Phylla, Earth's Ocean Gate Keeper, was unable to close her ocean gate to prevent the spill from reaching Andros. She goes through to warn Lemmy, Andros's Ocean Gate Keeper. They try to converge their powers to stop it but failed. The toxic waste travels towards the Andros prisons.
After their concert, Bloom encourages everyone to help clean up the ocean. They all head outside, but Bloom notices Sky's distance and unhappy demeanor. When she talks to Flora about it, Flora tells her to talk to him about it. Bloom takes her advice and goes talk to Sky. Sky himself, helping clean the tables with Brandon, vents to him. Brandon is somewhat in disbelief that Sky believes that a mere pendant is key to happiness and everlasting love. But he encourages Sky to be strong and talk to Bloom as he sees her enter the bar. He leaves and allows the couple to talk.
However, Sky is unable to answer Bloom and only tells her that he lost something. She does not push for an answer but looks away, sad and returns to continue helping with the beach clean up.
With his increased power, Tritannus and the Trix breakout of the prison. Before leaving, he learns that he can transform people into mindless mutants who obey his every command. He does this to the prison guards. He also absorbs Phylla and Lemmy's powers to open and close their respective ocean gates. He then declares his goala: travel to the Infinite Ocean and rule the Magic Dimension. He also returns the Trix's powers that had been stripped from them. But in doing so, uses all the toxins he had absorbed.
Tritannus and the Trix then go to Earth so Tritannus can absorb more pollution and become more powerful. After forcing two goons to dump the toxins into the ocean for Tritannus, who regains his powers, the Trix notice magic is in the air. Angered, Darcy demands to know who is responsible for this. One of the goons answers "the Winx", and this enrages the Trix. Seeing that, and for Icy, Tritannus orders his new mutant followers to seek and destroy the Winx.
The mutants arrive at the beach front where everyone is cleaning, and attacks. The Winx successfully chase them away but follow them to learn where they had come from. They are surprised by the Trix. Flora, Tecna, and Aisha continue following the mutants while the other three deal with the Trix.
Flora, Tecna, and Aisha are swimming in the ocean and all three notice their Believix wings failing them. They eventually locate the leader of the mutants. At first Aisha does not recognize the monster but after some fighting, she takes a closer look and realizes it is her cousin, Prince Tritannus. Tritannus smirks at her but when he hears Icy (who is surrounded by Bloom, Musa, and Stella) calling for him to help, he musters all of his powers to toss them aside.
He weakens a bit, showing some of his more triton features and confirms Aisha's initial suspicions. He runs for it, opens Earth's Ocean Gates, and escapes Aisha, Flora, and Tecna. The Winx and Specialists regroup and the girls prepare to leave for Alfea. Tritannus and the Trix swear they will destroy their enemies, together.
- The Winx hold a benefit concert to clean up the oil spill.
- Tritannus absorbs the oil spill and becomes a monster.
- Both Icy and Tritannus develop huge romantic crushes on each other.
- With his new powers, Tritannus turns the Guardians of Andros prison into a new breed of mer-monsters, the mutants, as his minions.
- Tritannus allies with the Trix and plans to rule the Magic Dimension.
- Tritannus took the powers of two Selkies to open the gate to Earth with the Trix so as he can absorb more toxic waste from the oil spill.
- Tritannus restores the powers of the Trix.
- On Earth, the Trix learn that the Winx brought magic back on Earth.
- While trying to follow Tritannus' minions in the sea, Flora, Aisha and Tecna realize that their wings are slow and stiff underwater due to the deep pressure of the water.
- Sky starts avoiding Bloom.
- Magical Echo - Used by Musa against the mutants.
- Summer Thunder - Used by Flora against the mutant.
- Fire Arrow - Used by Bloom against the mutants.
- Dancing Flames - Used by Bloom to protect herself from the Trix's attacks.
- Solar Storm - Used by Stella twice, first against the mutants, then against the Trix.
- Underwater Breath - Used by Aisha to let Flora, Tecna and herself breathe in the ocean.
- Sonic Screen - Used by Musa against the Trix.
- Dragon Heart - Used by Bloom against the Trix.
- Morphix Wave - Used by Aisha in a convergence with Mega Watt and Autumn Wind.
- Autumn Wind - Used by Flora in a convergence with Mega Watt and Morphix Wave against Tritannus but failed.
- Mega Watt - Used by Tecna in a convergence with Morphix Wave and Autumn Wind against Tritannus but failed.
- Morphix Staff - Used by Aisha against Tritannus.
- Tritannus' new mutation powers are limited. When he uses all the toxic waste, he regains his original triton form.
- When Tritannus' minions were attacking the people on the beach, Roxy did not transform to help out the Winx to fight back.
- Judging by how the Trix react to magic on Earth and how the Winx react to them, it seems that the Trix had been in prison ever since the end of Season 3. Thus, this is probably the first time they see the Winx in their Believix form.
- The Trix are heavily outmatched by the Winx in combat. Darcy and Stormy get defeated after the first three spells from Musa, Bloom and Stella.
- Roxy no longer has blond streaks in her hair. It is unknown if that is the new re-design for her or just a mistake during the production.
- During the fight scene on the beach, you can see a guy that looked and dressed like Riven from Season 1 fleeing alongside a girl.
- A new part in Bloom's Believix transformation sequence was added in this episode before her wings are materialized.
- During the concert, when they perform their new song, you can see Clarice cheering the Winx in the corner.
- Sean Schemmel, the 4Kids voice actor for Valtor (Baltor), returns to lend his voice to one of the merman guards.
- This episode's correct production code is 502.
- This is the third time the Trix have teamed up with a main villain.
- The "Rise of Tritannus" full episode was re-uploaded or uploaded onto Nickelodeon USA site.
- When Icy grabs the cell bars while informing Tritannus why she and her sisters were imprisoned, she had two left hands touching the bars, then her right hand keeps disappearing.
- Many Alfea fairies, who should not be on Earth can be seen during a farewell concert.
- When Musa defends two children from a mutant, some parts of her hair is missing.
- While on the beach, at one point, Bloom's wings are pink instead of light blue.
- When Bloom summons her Dancing Flames spell her gloves are missing.
- When the Winx confront the Trix, they were on the beach but in the next scene, they are above the water with only Bloom present. In the same scene, Bloom's wings are shaped differently.
- There are times where Flora's bangs do not have their highlights or is a darker shade.
- Just like in the previous episode, there are times where Bloom's wings are drawn incorrectly.
- In one scene where Stella was battling a mutant, Riven can briefly being seen wearing his season 1 outfit.
“I can't believe my father sent me here and made my brother Nereus crown prince.”
“So unfair. You obviously should be king.”
“If I could get my hands on my trident, I could get us all out of here!”
“So many people here are out here working!”
“I know, music can really inspire people to do the right thing.”
“Yes, but sister, have you noticed? There's something in the air here...”
“I thought you three were in jail, again”
“We couldn't stop him. Our magic is too weak underwater.”
“Icy, I promise you. We will destroy those fairies!”