This essay explores the role of flame in Heidegger's 1943-44 lectures on Heraclitus (GA 5 5). Specifically, I trace a tension that unfolds within the text between two flames: namely, "the flames of presumptuous mismeasurement" characteristic of modernity, and the flames of beyng. As I show, in GA 55 Heidegger argues that a certain Seinsvergessenheit has come to dominate the modern world and has resulted in an attitude of hubris on the part of the human being. As a corrective to this hubris, Heraclitus's thought serves as a reawakening of the meaning of being (as clearing). Heidegger, for reasons which I explore in the essay, understands both the forgetfulness of being, and being itself, in terms of flame. I trace the origins and perimeters of these two flames, marking the character and consequences of this conflict, having recourse to the Heraclitus lectures as well as a number of texts that inform them. I then conclude by broadening the scope of the conflict by examining the role that Christianity plays in fanning the flames of modernity (for Heidegger).