Taking advantage of the fact that his niece Carlota does not know what to do with her future, like so many young people today, Luís decides to fulfil an old promise and invites her to accompany him on his second adventure with the famous archaeologist Eudald Carbonell. The three embark on an extraordinary journey into the past that will bring them to travel four continents in search of the keys that will open the doors of the future to humanity, and maybe also to Carlota.