The story focuses on Asterix and Obelix helping train up the nephew of their village chief, only to find themselves contending with a visit by men from the frozen north raiding their lands in search of learning about fear.

In the rebel village of Gauls in Armorica, Chief Vitalstatistix receives a message from his brother in Lutetia (present-day Paris) that his teenage nephew, Justforkix, is being sent to him in hopes he can be trained as a warrior.

While Cacofonix breaks up the performance - and gets promptly struck down by Fulliautomatix, the blacksmith, for resuming his music - Justforkix suggests his talents would be better appreciated in Lutetia.

When the chief demands he teach the Normans fear, Justforkix fails to understand what he means in his frightened state, and is held prisoner.

When Asterix and Obelix learn of his kidnapping, they promptly visit the Normans resulting in a fight with them, with a Roman patrol accidentally getting caught up in the moment when they investigate.

Asterix eventually has a meeting with Timandahaf, who explains their mission to him, prompting him to send Obelix back to find Cacofonix.

The film received mixed reviews upon release, with praise on its animation quality and voice cast, but criticism of the script.