The Oresteia of Aeschylus (458 BC) is a prodgy of Ancient dramaturgy, first for the ambiguous and metaphorical treatment of the plot but, fundamentally, for its structuring over a familiar rite for the Athenian public, namely Bouphónia. This essay shows how the ritualistic substract is explored in the first piece of the trilogy - Agamemnon, and how the playwright maximized the cathartic effects of its spectacle.