Julius Caesar is celebrating his victory over all of Gaul, but Lucius Detritus has kept from him that one village has managed to resist them. Detritus travels to the garrison near the village where Caius Bonus (Crismus Bonus), the garrison's commanding Centurion, explains that the Gauls have a magic potion, which makes them invincible. Detritus decides to capture the potion for himself, and hearing that the clever Asterix and permanently invincible Obelix are the backbone of the Gaulish forces, attempts and fails to eliminate them.