Julius Caesar receives an unusual gift from one of his commanders: Kakofoniks, the famous Gaulish bard. Unaware of his situation, our hero is convinced that he is going to perform. Caesar, however, shows no interest in Kakofoniks's musical talent and, having concluded that he is unfit to be a gladiator, decides to throw him to the lions during the forthcoming Games. Asteriks and Obeliks rush to his rescue and, in order to get into the Colosseum, where their companion is to be put to death, they decide to become gladiators.