Towards the end of the sixteenth century, a group of musicians accompany a young woman bitten by a tarantula, Anna, on a pilgrimage to San Paolo di Galatina in the north of Puglia. During their journey they meet some extraordinary characters and experience a number of adventures, but the most important personage they meet along the away is the Pope's envoy who is travelling to San Paolo to investigate the violent crisis that is shaking the region and which has taken the form of a kind of exorcism accompanied by dancing and music called "tarantism". As he tries to explain to the faithful that the bite of a tarantula can not be the cause of such grave upheavals, the bishop finds himself the involuntary witness of the power of this extraordinary phenomenon. As to Anna and her musician friends their only remedy is the age-old archaic tradition of their forefathers.