The druid Panoramix forgot the recipe for the magic potion after receiving a menhir on the head - While Abraracourcix, leader of the indomitable Gauls, has just been challenged by one of his counterparts during a battle of the leaders.
Where the Romans, after being constantly embarrassed by Asterix and his village cohorts, organize a brawl between rival Gaulish chiefs and try to fix the result by kidnapping a druid along with his much-needed magic potion. I'm not giving anything away when I tell you, it doesn't go as planned.