A couple takes on a homeless teenager. The trio forms a family-like community that seems to work extremely informally and without many regulations. But then the harmonic situation escalates as the boy falls in love with his "adoptive mother".

Argenteuil, July 1973. Five unstable, insecure buddies pass the boredom by pilfering in the stores and revving up their motorcycles. On the eve of July 14th, during a trip to Bastille, a motorcycle paradise, one of them, Roger, gets into a fight with a policeman and is wounded. While fleeing, he meets a young "runaway" who helps him escape the search and rejoin Anne, "his wife". Despite a rather incredible maneuver, the two boys break into an apartment and kidnap the occupants. Anne and Roger don't manage to reach each other "discreetly", and the adventure ends stupidly: surrounded by the police, Roger makes a false move and throws the motorcycle into the ditch. When they get out of hospital or prison, life starts all over again.

This story is set in the 13th century, in Britain, where Lancelot, who was raised by Vivian, the Lady of the Lake, becomes one the Knight of the Round Tables and falls secretly in love with Guinevere, the wife of King Arthur, for whom he wants to accomplish many deeds.

Young doctor Garondet is summoned by renowned Professor Orloff. At Orloff's castle, Garondet discovers that the mad scientist has created an invisible yet murderous apeman.