After learning about the Legendarium, the Winx travel to the Lost Library of Alexandria so the indestructible book can be locked away for good.
Stella is busy designing her clothes while some insects enter her room. She screams, shouts and gets out of her room. Bloom, Musa, Tecna, and Aisha are also annoyed by the insects and see that they belong to Flora. Flora summons a Treemans Orchid to lure the insects back to their homes. Roxy enters the room and asks the Winx to help her transform Griffin back to her real form. Flora tells Roxy and the Winx to come to her room where she gives Griffin a potion she made from her plants immune system, the potion looks as though it is working, but it fails and Flora suggests Roxy to ask Professor Palladium for help. Roxy leaves the room after thanking the Winx, when Griselda comes in and informs the Winx that Faragonda has summoned them to the History of magic classroom.
There, Daphne and Faragonda tell the Winx about the Legendarium and Eldora, a fairy godmother who used to be the keeper of the Library of Alexandria until it was lost. Daphne also tells the Winx about the Library of Alexandria which is located in Egypt, Earth. She tells that Eldora kept a diary, where all of the secrets of the Legendarium are written. Because of this, Daphne, Faragonda and the Winx plan to go to the Lost Library of Alexandria and reasons out that it is a field trip.
At Cloud Tower, the Trix spy on them and plan to steal the diary from them.
In the other side, the students of Alfea, Lorie, Evy and Carol are ready to leave with the Winx while the Trix arrive and Darcy turns them into frogs. The Trix disguise themselves into the three girls. When the Winx, Daphne and the Trix (disguised as Lori, Evie and Carol) are about to leave, the Specialists and the Paladins come to visit Winx and Daphne. Tecna scolds the three of them, so Stormy gets mad and tries to attack her, but Icy calms her down. Stella takes her mini-fan out and creates a strong wind, which the Winx get mad for. Nex and Roy still fight over Aisha, so the Winx, Daphne, pixies and the Trix teleport to Alexandria.
In Egypt, Daphne gives trivia about the library and continues to find the library. Aisha finds a hot air balloon, which they rides on to find the library easier. The Trix plan to "have fun", so Stormy creates a sand storm. Bloom uses her magic to save the Winx. Daphne becomes worried, so Cherie stops the storm, which Darcy finds ridiculous. Flora uses her magic to feel the plants and detects them underground. Down there, Flora destroys a big rock and all of them enters it. Icy talks to Selina, who is in Cloud Tower, watching all of them.
Stella, scared, puts her hand on a wall, but discovers the entry and the others congratulate Stella. The Winx come into the library, and are surprised. Everything is full of gardens and palm trees, and Daphne says the Legendarium was between the walls that are in the library, but they do not know where to look because everything is great. The Winx begin to look, but there are thousands of books. Meanwhile, Selina summons some mummies and she orders them to attack the library. The mummies start attacking the team, and the Winx and Daphne transform. The Pixies help the Winx, and a mummy attacks the Trix but Tecna puts them in a cage to be saved. In the cage, the Trix say here they will begin to watch the fight and get to laugh, and the episode ends.
- Faragonda and Daphne tell the Winx about the Legendarium and Eldora.
- The Winx, Daphne and the Trix disguised as three Alfea students, Evy, Lorie and Carol, travel to Egypt to find Eldora's diary.
- The Winx arrive at the Library of Alexandria.
- Selina summons the Mummies of Alexandria to attack the Winx.
- Chlorophyll Bolts - Used by Flora against the Mummies.
- Morphix Trap - Used by Aisha against the Mummies.
- Bio-Rhythmic Flow - Used by Tecna against one of the Mummies.
- Digital Room - Used by Tecna to defend the Trix (in fairy disguise).
- Flame Spiral - Used by Daphne against a Mummy.
- This is the first episode since "Sibylla's Cave" that Flora and Roxy speak directly to each other.
- This is the first episode in which Roy gives a present to Aisha.
- Due to magic being brought back to Earth, adult humans can now see Pixies.
- It seems Daphne and Faragonda know about the Legendarium but it is not explained how they know that the Trix are in possession of it.
- Flora's potion bottle looks just like her rapid growth formula in "The Monster and The Black Willow".
- This is the first time all the Winx Club transform into Bloomix fairies.
- This episode aired along with Attack of the Sphinx In the US.
- This is the second time Flora was seen manipulating earth, the first was in The Secret of the Lost Kingdom via Energy of Mother Earth.
- In one scene, the behind part of Musa's hair is missing.
- In one scene, Thoren's gem is green instead of yellow.
“I don't remember these patterns being so... so alive.”
“Well thanks for that update, Tecna. How uplifting.”
“Get out of my boutique!”
“I bet this place is just crawling with rattlesnakes.”
“There are no rattlesnakes in Egypt, Stella.”
“This is not cool.”
“Wake up, Stella, this must be a nightmare.”