Martin, a child of the 21st century, through his telescope discovers Doctor Funes, the inventor of a formula to become young again and the envy of Doctor Moebius, who also wants to regain his youth. Martin goes to visit old Funes, but instead finds twelve year old Pablo, whom he shelters in his house without telling his parents what is going on. Pablo turns the biology teacher into a baby girl with a pacifier, and a group of the elderly into children. Martin dreams of a world of only children, but Doctor Moebius steals the formula, not knowing that its effects are unpredictable.

Ana, a nine year old girl, arrives with her mother to an isolated beach with the intention to rest and to know the sea. There, she discovers that they are under a terrible threat, therefore she is obligated to look for help with her father in order to save her mother.