Panaromix betrayed his friends: he made a pact with Caesar and went with him to Las Vegum, city of entertainment in the heart of Rome. Asterix, Obelix and Idefix leave for Rome to understand why Panoramix did what he did. Caesar has two new strong allies: Larry Craft, his new right-hand man and Boss Demath, a 10 meter giant who will give our heroes a hard time.