Reina Runa (Aventura total 6)

For millions of years, Eternia was a free planet. But Councilor Fiotto usurped power, banished the king, and turned Queen Runa into a tyrant who enslaved the Eternians. Millions of kilometers from Eternia, Lia and Ulysses signed up for Total Adventure, an elective course taught by Professor Hache, because they had no other choice. What Ulysses and Lia didn't know was that their destiny was to help the Eternians, nor that, aboard the spaceship Serendip, piloted by the robot Roxlo, they would travel to Eternia to experience a great adventure. A true Total Adventure. In this sixth book, Lia has new plans. New plans that Ulysses isn't entirely sure about. Lia wants to return to Eternia and visit Queen Runa to talk to her. But they have a problem: the rellesca has played a trick on them again, and they've started turning blue... in the middle of the schoolyard! And to make matters worse, they don't have Falstaf's ointment. Clearly, the only option is to hide, board the ship, and travel to Eternia.