In the year 50 BC, Gaul is occupied by the Romans - nearly. But the small village of Asterix and his friends still resists the Roman legions with the aid of their druid's magic potion, which gives superhuman strength. Learning of this potion, a Roman centurion kidnaps the druid to get the secret formula out of him.
Strange things are happening in the evening at the mansion: glass things break without any apparent reason. Professor Calculus, somewhat apathetic to the whole series of events, leaves the following day to attend a conference on nuclear physics in Geneva. Foreign powers get wind of his work and send their agents to investigate.
