It's the night of the shooting stars on Magix and the Winx are ready for a magic party at Alfea. But a little creature called Twinkly reaches them after a long journey, bringing an urgent message: they are the only ones who can save the stars!

The Winx, accompanied by Twinkly, reach Lumenia. There, Queen Dorana explains to them that the stars of the Magic Universe are in danger. She asks them to find out what has drained one of Lumenia's rivers of light, and the Winx find out it was because of a black magic sphere that blocks the flow of the river. After blowing up the sphere, they go underground where they battle two lava golems and a golem robot. After defeating the golems, Valtor's mark appears in the air, revealing to the Winx that he is still alive and back into action. After restoring the dried river of light, the Winx return to Dorana, who thanks them for saving the river. She then tells them that in order to save the stars, they will need a new power. Now that the river of light is restored and along with that Dorana's powers as well, she grants the Winx a new power: Cosmix.

The staryummies, led by Obscurum, absorb all the energy of Lumenia's core, causing the star to sink into darkness. The Winx use their new Cosmix powers to battle the staryummies, and eventually manage to make them escape. Though it seems the Lumenia's core is lost for good, Bloom comes up with the idea of using a convergence spell on the core itself, in order to try to restore it. Thanks to their new Cosmix powers, they manage to restore the core successfully. The Winx then throw a party in honor of the Lumens. Meanwhile, however, Valtor is preparing to attack Peripla, a star-ship that fly across the space.

At Alfea, Sky is preparing a romantic picnic under the stars for Bloom. But his surprise gets destroyed when the Winx have to leave for a new mission: they will need to save Peripla, a star-ship, from Obscurum and the staryummies. In order not to expose themselves to the lumens of Peripla, Twinkly comes up with the idea of the Winx posing as intergalactic pop stars. The Winx arrive on Peripla, and start a concert in honor of the Peripla lumens.

The Specialists are in charge of tracking down a mysterious ruby thief who landed on Peripla, and Riven finds him. a chase ensues between the two, But Orion manages to escape, along with the ruby diamond of the core of Peripla. Meanwhile, the Winx have to face an asteroid monster sent by Valtor. The Specialists eventually manage to capture the ruby thief, who's named Orion, and he appears to be a star scientist determined to save his home planet, Prometia, at all costs. The Winx agree to help him restore Prometia, and decides to travel there with him.

The Winx and Twinkly follow Orion to Iridia, the star that lights Prometia. There, they try to restore the core of the star, unsuccessfully. They discover that the planet's core has been completely destroyed, that even with their Cosmix powers they cannot repair it. Twinkly finds her friend Lumilla and the two have a little tea party. Orion, disappointed by the failure of the Winx to fix the core of Iridia, is contacted by Valtor, who offers him a deal: if he helps him to take out the Winx, he will save Prometia, Orion's home planet, by restoring the core of Iridia.

On Prometia, the Winx fall into the trap set up by Orion and Valtor. Fortunately, Stella and Flora manage to escape from the trap and transform in order to free their friends just in time. The Winx then creates a new temporary core of light for Prometia to save the star for the time being, by using a new spell: Cosmix Power Supernova. Meanwhile, on Iridia, Obscurum arrives at the star and transforms all the lumens of the star, including Lumilla, into staryummies.

The Winx go to Andros, Aisha's home planet, to participate in the festival of the kingdom. an old friend of the Winx, queen Ligea, attends the festival as well. Meanwhile, Obscurum and the staryummies attack Gorgol, the underwater star of Andros. The Winx, aided by Nex, decides to go on a new underwater mission to save Gorgol, and to do so, they use their old power, Sirenix, and dive into the ocean of Andros. Underwater, they face the Hunter of the Seas, a predatory monster sent by Valtor. They manage to defeat it by trapping it in a cave with no way out.

In the depths of Andros, Aisha must save Nex, who is in grave danger. Meanwhile, the other Winx try to prevent Obscurum from escaping after the staryummies completely drained the core of Andros, but unfortunately, they are imprisoned inside the core's cave and are attacked by some magical anemones, special flowers that protect Gorgol. After all the Winx, except Aisha, falls into sleep because of the anemones' attack, it seems it's the end of the Winx Club. Aisha eventually understands how to calm the anemones - By using the singing of the lumens of Gorgol.

Valtor decides to attack the star Hypsos, which is located in the star's constellation of the Hydra. When they discover that Hypsos is in danger, the Winx set off on a new mission to save the star. When they arrive on Hypsos, Valtor then uses his powers to turn the constellation of the Hydra into the actual Hydra monster. While the Winx face the Hydra, Musa saves Riven and the two seem to draw closer. The Specialists come to aid the Winx in fighting the Hydra, but it seems nothing affects it.

Valtor and Obscurum intend to attack a new star, Syderia, and to do so they decide to adapt a different strategy: deception. Obscurum goes to Syderia, and while all the lumens of the star are asleep, He cast a spell on them. He then sends the staryummies to drain the core of the star. Meanwhile, at Alfea, Twinkly informs the Winx that Syderia is under attack. When the Winx come to the rescue of Syderia, they discover that the lumens that inhabit the star are convinced that the fairies have come to steal the treasure of their star, and the Winx are forced to escape them and hide.

Bloom goes to earth to throw a surprise party for Vanessa, her mother's birthday. Valtor then decides to attack the Sun, in order to destroy the Earth and hurt Bloom's family and friends.

While the Winx are trying to stop the attack on the Sun by the Star Troll, the Specialists have to deal with the two dark star giants that are about to attack Gardenia. Meanwhile, Obscurum goes to Lumenia to claim his throne, and traps Dorana in a magic cage. Valtor tries to take possession of Bloom's Cosmix power by threatening to destroy her world, family, and friends, So Bloom decides to give up her Cosmix powers to him. Valtor tries to absorb the powers, but is rejected by the power itself and is sent to the dimension of limbo. Twinkly arrive at Gardenia with her min artificial core made by Orion, and Sky uses it to blast one of the star giants into pieces, though there is still another star giant left, and no other mini cores. On the Sun, the Winx battle and defeat the Star Troll, which releases the energy sparkles of the Sun's core into the air. The Winx capture the sparkles and hold it in position until Bloom comes back with her Cosmix powers and helps them to keep it at bay.

After their last battle, the Winx relax and enjoy a lesson with professor Paladium in the Alfea simulator. Meanwhile, Valtor informs the Trix that he bonded them with him so they cannot escape, and then sends the Trix to capture the Wishing Star, though they fail when the star scatter itself into pieces across the galaxy to prevent the Trix from capturing her and bringing her to Valtor. One of the pieces, a star-shaped box, flies to Lumenia, landing in Dorana's throne room along with Twinkly. Dorana and Argan then send Twinkly to call the Winx.

The Winx, using their new and greater Enchantix powers, battle the Trix inside the Pinball Prime MiniWorld, in the quest of capturing the Compass of the Wishing Star. Every time someone is about the catch the compass, it escapes and bounces around in pinball-shaped world. After a long and funny encounter of the Winx with the Trix, the Winx win the quest and capture the Compass of the Wishing Star. They go back to Queen Dorana, who puts the compass into the Star Case, which activates it. The quest of the Prime Stars has now officially begun!

Faragonda and Griffin announce the beginning of the Sparks Festival at Alfea. While preparing a new concert for the festival, The Winx are alerted by the Star Case that a prime star is nearby. They go down into the Alfea well, where they find a Star Screen - a portal to a Prime MiniWorld, where they go through several levels of the quest of the first prime star, and the Trix follow them there as well. Eventually the Winx manage to capture the first Prime Star, and goes back to Alfea to hold their concert, while the Trix go back to Valtor, who's angry at them.

The Winx goes to Solaria, Stella's home planet, to find the second Prime Star. After a clue from the Star Case, They believe that in order to find it, they must make a dress fit for a queen.

While Bloom is concerned about Sky's safety, having not heard from her for some time, the Star Case informs the Winx that the third prime star is beyond the clouds of Monoceros, home of the winged unicorns.

As they fly past the clouds of Monoceros, the Winx hear someone shout for help and find Diaspro, and Sky not far away struggling with the black unicorn. Flora realizes that the animal is not evil and the fairies manage to calm it thanks to a rainbow show of the other unicorns. The Monoceros Lumens explain to the Winx that the animal no longer trusts anyone after the last person in whom he placed his trust broke his horn. Surprisingly, the black unicorn decides to bind himself to Jasper, who takes advantage of his help to leave the star, while Bloom and Sky quarrel because the Specialist did not tell her to be on a mission with Jasper.

The Winx reach Linphea and enter the Great Forest to retrieve the fourth prime star, but, having reached the Green Heart, they are attacked by the Trix. Even Miele went into the forest, despite Flora having forbidden it because it was dangerous, to help the fairies: Darcy takes advantage of it and, after making Miele pass out with a spell, takes on her appearance, pushing Flora to help her and thus taking her prime star without interference.

The Star Case takes the Winx to Melody, Musa's planet, where they discover that the fifth prime star has been incorporated into the crown destined for the winner of the dance competition organized annually by Princess Galatea. The Winx and Trix, with the exception of Musa and Darcy, thus find themselves competing on the track in one-on-one challenges to grab the crown. Meanwhile, Musa visits her father and receives an unexpected visit from Riven, who is however under a spell cast by Darcy.

Darcy tries to harm Musa by pushing Riven, hypnotized, to attack her, but the Specialist manages to rebel from the witch's spell of illusions by showing the girl how strong the feelings towards him are. Meanwhile, the other Winx are engaged against the Trix in the dance competition, but in the end it is Stormy who wins the crown; however, the prime star vanishes from his hands and appears to Musa and Riven, as the requirement for conquering the star was to find harmony.

At Alfea, Tecna and Aisha must pass an exam assigned by Professor Palladium within a time limit, but the two do not agree on how to act and end up failing. At the end of the lesson, while the two quarrel, at six fairies the Star Case appears, guiding them to Coralia, where the sixth primary star is located. Since Aisha thinks she is in the sea and Tecna is in the mouth of the volcano, the two fairies have another spat and so the girls decide to separate: while Aisha, Musa and Flora head towards the sea, Tecna, Stella and Bloom they go to the volcano, where they encounter large lava golems that protect the core.

The Star Case brings the Winx to Dyamond, a frozen and deserted world on which the seventh and last prime star is hidden.

While the Winx save Sky from the frozen lake, Icy meets the white fox: it turns out that Dyamond is the planet of the witch and that the fox is actually her sister Sapphire, transformed into an animal by a shaman witch that years before she arrived on Dyamond and froze everything. Since then, Icy has vowed to become a witch stronger than her and to break the spell. The white fox accompanies the Trix in the subsoil of Dyamond by the prime star, which however ends up in a tunnel, in which Sapphire slips to retrieve it. In an attempt to enlarge the opening with magic, Stormy causes a collapse of the vault, forcing the witches to escape and abandon the primary star; the latter, however, appreciating that Icy has rescued Sapphire instead of abandoning her to danger, hands herself over to the witch.

The Winx reach Valtor's palace to try to defeat it and take the other prime stars. The group attacks the castle attracting the Trix to the outside and, while Bloom, Musa and Tecna face them, Stella, Aisha and Flora take on the appearance of the three witches to try to catch the stars; however, as they try to deceive Valtor, the real Trix return, forcing the Winx to fight against the wizard, who has turned into a gigantic demon monster. After hearing from Bloom that Valtor intends to destroy the Magic Dimension, Icy does not know who to give the prime star in his possession, but in the end she delivers it to the Winx in order to be able, one day, to save Dyamond and her younger sister.