Rosaria is a southerner who lives in Turin. Alone and with many sacrifices she raised three children, the youngest of whom, restless and rebellious, left home without giving any more news of himself. On the same night in which, unexpectedly, he returns to his mother, he is arrested for murder and indicted, among other things, for numerous rapes. Incarcerated with overwhelming evidence against him, it seems that there is no escape for him, also because he does not defend himself and assumes the attitude of someone who is hiding a terrible secret, thus appearing guilty in everyone's eyes. Only the mother persists in believing in his innocence, even improvising as a detective: she undertakes, once again alone, an investigative investigation in order to identify the true person responsible for the crimes and demonstrate Michele's innocence.