S5·E4 The Sirenix Book

Krystal attempts to heal Sky's memory, but the memory of losing the pendant of Eraklyon is causing the blockage, but only Sky knows where it can be found. Timmy helps Tecna update her phone to find the Sirenix Book, which the Trix secretly sabotage. While, searching for the Sirenix Book, the Winx find the fake one, which turns Tecna into a terrifying robot, whose mission is to find the Sirenix Book.