According to Heidegger, we are living in an ever worsening ?worldnight?, whose fundamental nihilism is due to an ?abandonment by Being? (Seinsverlassenheit) or a ?forgetting of Being? (Seinsvergessenheit). In this paper, I attempt to clarify the notion of an ?abandonment by Being? through an examination of two themes prominent in Heidegger's later philosophy: Being as ?event? (Ereignis); and the obscure ?mystery? or ?secret? of Being. ?Seinsvergessenheit? is interpreted as a forgetting of the mystery or secret of Being which is the (...) ?ontological difference? between Being and beings, i.e. between some concrete revelation of a world and the conditions which make possible any revelation whatsoever. Since these conditions make up that ontological structure which is Dasein and since Dasein is human being, to forget Being is to be in a condition of profound self?estrangement. The origin and growth of this condition constitutes the history of metaphysics, which unfolds as the history of a progressive increase in ?subjectivism?, culminating in the nihilistic ?will to will? as the mode of revelation of the modern world. Finally, Heidegger's two ?remedies? for Seinsverlassenheit are examined: the first, the need for a cultivation of ?essential thinking? is shown to be fundamentally sterile and unable, therefore, to bear the burden of world?transformation which Heidegger lays upon it, while the second, the exhortation to experience the ?thing? as ?assembler? of the ?foursome?, it is argued, does not grow organically out of Heidegger's central philosophical preoccupations, but represents quite a radical departure from them. (shrink)