The humble country life of Asterix, Obelix and the other villagers is interrupted by the sudden arrival of Justforkix, who has come seeking help. He reveals that his father, Doublehelix, has been imprisoned for a theft he did not commit...

Asterix promises to investigate and asks Justforkix to stay safe in the village. The two Gallic warriors head to Lutece to get more information from an acquaintance known to be well-informed about the rumors and intrigues of the city... And obviously, they won't find the answers they need on their long journey without a healthy dose of slaps!