Treasures Of Syderia.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. After going underground, the Winx gets trapped by the lumens and are about to be attacked by them. In the last second, Kiko and Knut come to their rescue. Knut starts making funny things that makes the lumens of Syderia laugh and therefore distracted, so the Winx escape without them noticing it. The Winx then discover that in the subsoil of Syderia there is a mountain of light crystals. They use their Cosmix powers to light up the crystals, and with the crystals light, Syderia is restored. Bloom has the idea of bringing a crystal fragment to Orion, so he can build new cores for the extinguished stars.