Building on Werth’s (1994) notion of ‘megametaphor’, in this thesis I examine the discourse-level conceptual effects of metaphor in five op-ed articles about the 2008 British financial crisis. I use these analyses to offer three contributions to debates in metaphor studies. Firstly, I attempt to offer a more detailed specification of megametaphor. I argue that whilst megametaphor is a useful concept to start an investigation of discourse-level metaphoric conceptual effects, Werth (1994) does not sufficiently differentiate it from the notion of ‘conceptual metaphor’ (see Lakoff, 1993; Lakoff and Johnson, 1980). I define megametaphors as text-driven discourse-level conceptual structures comprised of multiple metaphors. Secondly, I argue that megametaphors are situated within the broader cognitive environments generated in the minds of discourse participants as they take part in a discourse. Analysts therefore have to account for the relationship between megametaphors and the conceptual contexts in which they appear. I argue that Text World Theory (see Gavins, 2007; Werth, 1999) provides the best account of this conceptual context, and suggest that the text-world structures created in the minds of readers scaffolds the integration of individual clause-level metaphors into megametaphors. Finally, drawing on Werth’s (1977, 1994) notion of ‘double-vision’, Steen’s (2008, 2011a, 2011b) notion of ‘deliberate metaphor’ and Stockwell’s (2009) attention-resonance model, I propose a framework for describing the ways in which megametaphors ‘texture’ (Stockwell, 2009) the text-worlds in which they are situated.