The article establishes some parallels in attitude and analogies in decision-making between the fictional underground explorations depicted in Jules Verne's novel Journey to the Center of the Earth (1864) and contemporary engineering efforts to tap geothermal energy by drilling through the Earth's crust. It is argued that reconstructing these parallels can be a helpful way of uncovering previously little discussed assumptions and perhaps even deeply ingrained attitudes derived from specific perceptions of the geological underground. In the course of doing so, topics analyzed include the integration of old and new technologies, connections between responsibility and irrationality, failure as a normal stepping stone, or how unavoidable unknowns are being creatively incorporated into decision-making and practical strategies for probing into unfathomed depths.