Pocó is ready to be born and live the best day of his dog life! However, he is sent to the wrong family, forcing him to return to the Island of the Ilús, a mythical place where all animals live before they are born. Unwilling to accept this, Pocó wants to meet his real family, even if it means discovering a secret passage at all costs, a passage known only to Rinco, the leader of the rejected animals' clan. His best friend Oli helps him on this journey, even though Pocó has no idea that she is a spy for Gakra, an evil reptile who intends to invade the island and shake up the entire animal kingdom.