Tintin travels to the small kingdom of Syldavia where he is witness to a conspiracy against the young king, Múisc Áir XII. The plotters plan to steal the ancient Sceptre of King Ottokar, symbol of the new king's right to rule.
Fágtar leanbh mic os comhair dhoras tosaigh Asterix… ach cad as ar tháinig sé agus cé a d’fhág ann é? Níl tuairim ag Asterix agus Obelix conas aire a thabhairt do leanbán agus tá géarghá acu le cúnamh. Ach ná cuir an sionnach i bhfeighil na ngéanna, a deirtear!