En su travesía darán con el planeta Eternia, habitado exclusivamente por niños. Allí son confundidos por agentes secretos y apresados. ¿Conseguirán escapar? ENGLISH DESCRIPTION Ulises and Lia sign up to "Total Adventure", the extracurricular activity at school which is sure to live up to its name and take them on a total adventure! At their school, students can choose which extracurricular activity to join. However, it is against their will that they end up in "Total Adventure" with Mr. Hache, an old and cranky teacher. What Ulises and Lia don't know is that Mr. Hache is hiding a big secret and that they are about to embark on a thrilling adventure. Ulysses and Lia will almost reluctantly make their first space trip aboard the Serendip, professor Hache's ship. On their journey they will reach Planet Eternia, completely inhabited by children. There the locals believe them to be secret agents and are arrested. Will they be able to escape?