When Julius Caesar lands in Britain, a small village holds him and his Roman legions off while Queen Cordelia sends her officer Anticlimax to get help in the village of Gaul. At the same time, Asterix and Obelix are in Gaul trying to make a man of Justforkix, Chief Vitalstatistix's nuisance of a nephew. When Anticlimax arrives there, the villagers give him a batch of their magic potion. Asterix and Obelix accompany Anticlimax on his journey home and bring Justforkix along, hoping to make a man of him. In Londinium, Justforkix falls for the beautiful Ophelia, who happens to be Anticlimax’s fiancée, while Obelix falls for her teacher, the rigid Miss Macintosh. Distracted by their crushes, they misplace the cask that holds the magic potion.