This paper offers a sustained semiotic and political analysis of the Banquet Scene (Act III, Scene IV) in Macbeth by William Shakespeare, arguing that the scene constitutes the decisive site where signs begin to betray their maker and meaning collapses across psychological, linguistic, and political domains. Drawing on the semiotic frameworks of Ferdinand de Saussure and Charles Sanders Peirce, the study examines how the banquet—initially a ritual sign of order, hierarchy, and legitimacy—becomes a space of disruption with the appearance of Banquo’s ghost. The ghost operates as a complex sign (icon, index, and symbol), exposing Macbeth’s concealed guilt and destabilizing the political narrative of rightful kingship. Through close textual analysis, the paper demonstrates how the breakdown of language, the failure of ritual performance, and the erosion of shared signification produce a crisis of meaning that isolates Macbeth and undermines his authority. Integrating insights from cognitive, new historicist, and ecocritical perspectives, the study further shows that the scene reflects broader anxieties about sovereignty, social cohesion, and ethical order. It concludes that the Banquet Scene functions as a semiotic turning point, where the collapse of meaning precipitates the tragic disintegration of both the individual and the state.