O'Neill's one of the earliest dramas - Thirst (1913) deals with the typical attributes of human behavioural pattern when death threats man on the face of ontological degeneration and degradation. My article, by focusing on the three characters of the drama – the Gentleman, the Dancer and the Sailor who are put at the crisis point of existential ladder, will concentrate on how the play vividly dramatizes the idiosyncrasy of appearance on the set of madness and the resultant reflection of the display of barbarism at the face of existential decadence