During an party organized for the new year 2000, Arthur refuses to give his girlfriend Lucie the child she dreams about. But while the party runs, he discovers in the apartment, a secret passage that drives him in 2070, in Paris that has changed a lot. At this date, the sand and the desert have invaded the city and the whole country. There is no longer cars and the population seems to have become rural.
An old man named Ako presents to him. He says he is his son, a son who is not born yet. Although incredulous, what surprises him is that the strange man presents him photographs of Lucie and him holding on their baby. Further, Ako presents him his whole family and descent. He meets his daughter-in-law, his grandson and his great-grandchildren. The old man implores him to conceive him in order that he and all his family exist. To convince him of the emergency of his acts, Ako shows him his leg : under the cotton of the pants, his leg is little by little disappearing as if he should never have existed.
Arthur thinks that these peoples are crazy. When he attempts to turn back to find his friends who celebrate, Ako prevents him to do it and ties him on a chair. One after another, the members of his family are going to succeed to attempt to convince Arthur that he has to procreate. Ako is even going to propose Arthur to meet Mathieu, one of his best friend. But the vision of a 94 years old man, freshly deceased in addition, perplex him...
Spoiler ! the end of the story is revealed below…
With the assistance of his great-grandson, he returns to his period, awaited by Lucie. But facing the insistence of the whole family who also arrives in the 21st century, Arthur is obliged, after asking his girlfriend, to announce them that their current condition does not authorize them to have a child now. In the morning, while the party ends and everyone is returning home, Arthur, for whom the recent experience was suitable, decides to make love to Lucie and to offer her the so desired present. That day, a light breeze already transports some sand in the streets of the capital.