Between The Earth And The Sea.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. Meanwhile, Valtor decides to personally take the star and destabilizes the core of Coralia, overheating it and activating the volcano, which begins to erupt. Tecna reaches the other three Winx to ask for help and together with Aisha she discovers that the primary star is in a shell, but, as they are about to take it, Valtor appropriates it by leveraging the fairies' desire to save Coralia from the explosion of the volcano. The Winx then leave him the primary star and split: while Aisha and Flora save the lumens, Tecna and Musa reach Bloom and Stella and, with Cosmix powers, cool the core by stopping the eruption. Despite the mission's failure, Aisha and Tecna make peace by understanding that they have both been too stubborn.