Inspired by true events, My Son, My Son, What Have Ye Done? is a story of ancient myth and modern madness. An aspiring actor performing in a Greek tragedy, Brad Macallam commits in reality the crime he is to enact in the play: he kills his mother. The film opens as police officers arrive at the scene to find an elderly woman lying in a pool of blood. Stunned and curious neighbors are gathered outside. The suspect has barricaded himself inside a house across the street, and he appears to have taken hostages. Two friends he had urgently telephoned earlier that morning arrive, but too late. As they and the neighbors—witnesses to the bizarre killing— try to come to grips with what has happened, they tell their stories to the detective in charge of the crime scene.