In the Kingdom of Andros, Aisha's uncle, King Neptune plans to make his son Nereus Crown Prince. The ceremony is disrupted when Nereus' twin, Prince Tritannus attacks and is sent to the prison of Andros where he meets the Trix.
It is a day of interruption as Tritannus stops Nereus from being crowned and the Winx concert is halted when an oil tank nearly explodes.
The Winx advertise their concert in Gardenia at the Frutti Music Bar during the night by using their powers to impress the people of Gardenia. After they advertise their concert, they meet Roxy at the Frutti Music Bar. She tells them that it is her last day working at the Frutti Music bar as she was accepted in Alfea. She shows Bloom an admission letter. She is thankful to Bloom and says that Bloom helped her a lot like a big sister, reminding Bloom of her sister Daphne.
Meanwhile, at an oil tank in the middle of the sea of Gardenia, the machines are in a very bad condition to such an extent where it may lead to an oil spill. The Winx check out a smoke occurring there, but luckily, no oil spill occurs after Tecna scans it with her techno device. The Specialists are on their way to meet the Winx at the Frutti Music Bar. Sky is so nervous as he is about to give Bloom the Pendant of Eraklyon to prove his love to her.
When the Specialists arrive, the Winx happily greet them. The Winx hang out with the Specialists where Helia gives Flora a special origami while Brandon is serving Stella a glass of carrot juice which she does not like. Sky is telling Bloom about his summer and when he is about to give Bloom the pendant, Musa interrupts their conversation. Kiko who wants to drink the carrot juice in front of him almost has Sky drop the precious pendant. Flora sees what is in Sky's hand and asks him whether that is for Bloom and he answers yes.
Bloom is searching for Aisha as she sat far from the rest of them. Aisha is crying missing Nabu when she sees Nabu's photo on her phone. When the Winx approach her and ask her whether she is fine, she quickly changes Nabu's picture to Tressa's picture and says that she is alright. Aisha introduces the Winx to her family's picture and says that the coronation day is on that day where her uncle will pick one of his sons as the next underwater world king of Andros. A moment later, Tressa calls as the ceremony is about to begin and she picks it up.
Tressa is in King Neptune's throne room, where mermaids, tritons, and selkies come to watch the historical moment of underwater world of Andros. The Winx and the Specialists greet Tressa through Aisha's webcam on her cellphone. Two mermaids are talking about the ceremony when they enter the throne room. Tritannus, who sneaks behind them (in a mask) overheard their conversation in which one of the mermaids says Tritannus is not great, causing him to be angry.
Tritannus does not appear so as a result, King Neptune continues the ceremony without him. He honorably announces Nereus as the next underwater king of Andros to the Andros citizens. The crowd cheers and applause and hail Nereus as their next king. When King Neptune is about to give him the crown, he is attacked by a stranger causing him to be furious. A fight breaks out between King Neptune and the stranger until the stranger's mask is removed accidentally.
Everyone gasps as it is Tritannus. Tritannus then explains his jealous feeling about his brother to his father. His father, angrily commands the guards to put him in the dungeon. Aisha's connection is lost making her worry about the chaos that is happening on Andros.
Suddenly, a loud, earthshaking rumble is heard. The Winx and Specialists rush out to see the oil rig had exploded; the oil fires trapping the workers. The Winx and Specialists rush to save the workers. While trying to save one of the worker, Sky drops the Pendant of Eraklyon. He tries to grab but instead he and the worker fall off his wind rider. Bloom catches Sky before he fell into the water but could not catch the worker.
Aisha herself is swimming in the ocean, in search for breaching in the pipes. As she reaches it, her Believix wings start giving out. Aisha uses her morphix to seal the hole and also retrieves the foreman who fell into ocean. As she carries him up to the surface, her wings causes her trouble and has extreme difficulty maneuvering in the water. Eventually, she breaches the surface and Sky takes the foreman to shore. Aisha then informs her friends that the leakage will continue as the pipes are breaking. The Winx use convergence to purify and contain the spill. The convergence changes the oil rig into a more eco-friendly one. Though this does not appease Flora as there is still oil in the ocean, it is all they can do as they need to ensure the workers are safe.
The workers are taken care of the paramedics. Vanessa and Mike go to see Bloom and are worried about the oil polluting their beaches. Because magic is now back on Earth, it becomes more of issue as mixing pollution and magic can become dangerous. Bloom hatches an idea and decides to have tomorrow's concert to one of benefit. To preserve the Earth's oceans and maintaining the health of Gardenia's beaches. For Sky, he continues gazing at the ocean, upset at losing the Pendant of Eraklyon.
The spilled oil that the Winx were unable to contain continues to travel across the ocean.
- Seeing the other Winx with their respective boyfriends, Aisha misses Nabu.
- Tritannus disrupts the crowning ceremony of Nereus.
- An oil spill occurs.
- The Winx used a Believix Convergence spell to restore the oil tank, and at the same time making it become Eco-friendly.
- After restoring the oil tank, the Winx decide to hold the upcoming concert as a benefit to help preserve the Earth's oceans and the beaches of Gardenia.
- Tritannus was sentenced to the Andros prison for attacking King Nereus.
- Tritannus meets the Trix for the first time.
- When Aisha is underwater, she finds something is wrong with her wings and has trouble getting to the bottom of the ocean, realizes that Believix is just not powerful enough.
- Sky loses the Pendant of Eraklyon.
- Morphix - Used by Aisha along with Bloom's Fire Dragon to advertise the Winx's Concert.
- Sonic Blast - Used by Musa to advertise the Winx's Concert.
- Fire Dragon - Used by Bloom to advertise the Winx's Concert.
- Flaming Armor - Used by Bloom to defend herself.
- Fire Magic - Used by Bloom to make her way through the flames.
- Double Eclipse - Used by Stella to defend herself and the workers on the oil rig from the fire.
- Harmonic Attack - Used by Musa against the crane.
- Fire Catcher - Used by Bloom twice to absorb the flames from the oil tank.
- Techno Shock - Used by Tecna to absorb the oil spill.
- Oil Delete - Used by Tecna to delete the oil in the ocean.
- Constricting Vines - Used by Flora against the leaking pipes.
- Underwater Breath - Used by Aisha to dive in the polluted sea and to prevent oil to spread into the ocean.
- Purifying Wind - Used by Tecna and Musa in a convergence along with Crystal Water and Green Burst to create the eco-friendly machine.
- Crystal Water - Used by Aisha and Bloom in a convergence along with Purifying Wind and Green Burst to Create the eco-friendly machine.
- Green Burst - Used by Flora in a convergence along with Purifying Wind and Crystal Water to create the eco-friendly machine.
- The Season 5 premiere episode takes place sometime after the events of the fourth season and Magical Adventure left off.
- This episode's correct production code is 501. This was originally going to be the first Season 5 episode, but it was switched in the United States by the fifth season's fifth episode, The Lilo, which is a stand-alone episode.
- In the Nickelodeon clip for "The Spill", the clip was titled "Don't Cry over Spilled Oil: Masked Assassin".
- The oil spill is very similar to the events relating towards the B.P. Oil Spill in the United States.
- The season began on September 2, 2012 in USA.
- Nickelodeon UK beginning start of Season 5 is unknown but it might have started of somewhere in Fall 2012 as the current date is unknown.
- Nickelodeon Canada beginning start of Season 5 which remains a mystery as they have started airing or doing a Season 5 marathon which had began on June 17, 2014.
- In the iTunes Store which came in a package called Winx Club Beyond Believix, Vol. 1, it is listed as the second episode.
- This episode also marks the first time in the Winx Club TV series, the Winx are seen/shown staying in and wearing their Season 5 civilian outfits.
- This is also the first Winx Club TV series season premiere episode that follows right after the fourth season finale episode.
- This is Season 5's premiere episode that show the Winx's new civilian outfits, replacing Season 4's civilian outfits.
- This also marks the first showing of the show's opening which contains a few scenes from episodes two to thirteen of Season 5. It also shows the two transformations which are Harmonix and Sirenix. It also marks the first showing of the ending with a scene from the thirteenth episode of Season 5.
- Later in the season, there will be two different sections which are directors. The Art Director for the first part are Simone Borselli and Cristiana Magrini, and for the second part the CGI Art Director is Vincenzo Nisco.
- In this episode, We're the Winx replaces Winx Are Back as the opening theme song, while Superheroes is replaced by Underwater Mission as the ending theme song.
- In the Nickelodeon dub, the song "We're the Winx" replaces Winx, You're Magic Now as the opening theme.
- This episode marks the first appearance of the Selkies.
- This is the first episode to be fully animated with flash animation. The first six episodes of Season 4 used a mixture of flash and 2D hand drawn animation.
- This is the first episode to air in the 2010s decade in general.
- The Trix make their first reappearance since Season 3 and Magical Adventure.
- When Bloom uses her spell, Fire Dragon, the lower portion of her hair is not colored in.
- When the girls walk towards the bar after advertising their concert, Roxy is managing the Frutti Music Bar and her hair is parted in the wrong direction.
- While Tecna is looking at her phone, scanning the locations of the pipeline breakages, she is wearing her Believix gloves even though she is in her Season 5 civilian attire.
- During one scene, all of the Selkies are seen in Nereus's ceremony. However, when Tritannus attempts to kill his brother, only Lemmy is seen for the rest of that scene.
- At some parts of the episode, Bloom's wings look different from how they are originally drawn.
- In one scene, while the Specialists were helping the Winx save the workers from the spill, Sky's gem was not blue.
- After strengthening her Constricting Vines, Flora's hair is positioned behind her wings instead of in front.
- When Aisha was trying to save a worker her wing edges are not turquoise in color.
- In two scenes, Stella's eye shadow in her Believix is baby blue instead of pale yellow.
- In some occasions, both Sky and Tecna can be seen in their old hairstyles from Seasons 1 - 4.
- When the Winx converge their powers, Flora's wings are incorrectly colored.
“I couldn't have done it without you, Bloom.You were there for me, just like a big sister.”
“Nereus, totally. And a complete sweetie. But Tritannus, well, he's kind of a psycho.”
“Tritannus is so not? They'll be sorry. Very sorry!”
“We did so much, but it still wasn't enough.”
“So pollution and magic could mix? Sounds like big trouble.”