Contemporary fantasy and science-fiction construct original story-worlds to distance them from the primary world of the reader. This cognitive estrangement is supposed to perform a critical function, serving as a way to comment upon the social, economic and cultural relations of the author's primary world. This paper offers a cognitively infused criticism of the emphasis laid on world-building in today's SF/F fiction. In the contemporary media landscape, the proliferation of world-building fiction is largely due to the desperate need for the limitless expansion of successful intellectual property franchises. Rather than the plausibility of character actions and story arcs, these intellectual properties depend on the plausibility of the world for their success. Contrasting M. John Harrison's Viriconium universe and Jeff VanderMeer's The Southern Reach Trilogy with the aesthetics of world-building fiction, I employ a historico-critical approach to explore the limits of inner consistency in speculative writing and the (im)possibility of these story-worlds.