In Montesano, Salento, during the festivities held in August in honour of Saint Donatus, patron saint of epileptics and the mentally ill, the power of collective suggestion causes strange phenomena and rituals to occur. Luigi Di Gianni, master of anthropological documentary, films the worshippers with Dionysian force as they writhe and scream as if in a pagan rite, showing how the content of the Catholic liturgy succumbs to the primitive passion of popular religiosity.