How do astronomers talk about black holes, and what does their language reveal about their thinking? This study applies conceptual metaphor theory and image schema analysis to black hole language in five canonical general relativity textbooks. The analysis sheds light on an implicit metaphorical foundation grounded in a few key image schemas that cut across all five texts. In contrast, explicit pedagogical metaphors vary substantially between authors but often fail to correct or displace the implicit mappings. The findings suggest that the metaphorical structure of expert language in general relativity is constitutive of the subject matter, with direct implications for how black hole physics is taught and learned.