The historian Carlo Ginzburg is renowned for his critique of modern, scientific reason and his articulation of an alternative form of knowledge which he labels 'conjectural'. This form of knowledge, supposedly more attuned to the historian's interest in the singular and specific fragment, as opposed to the abstract and universal concept, is so rooted in the practices of the prehistoric hunter that Ginzburg sometimes describes it as a 'venatic' form of deduction, binding 'the human animal closely to other animal species'. In this essay, I explore the ramifications of this alternative form of knowledge, attending especially to its relationship to the modernist theme of 'primitivism'. I do so by juxtaposing Ginzburg's critical appraisal of Arthur Conan Doyle's most famous literary invention, Sherlock Holmes, and Rudolph Fisher's own literary invention, John Archer, the physician who sometimes aids criminal investigations in African American Harlem. I argue that the differences between Archer and Holmes draw attention to some troubling implications of Ginzburg's historiographical argument. Folding this analysis on itself, however, I also suggest that what might be at stake, when Ginzburg insists so troublingly on the importance of the singular, venatic trace, is the evocation of Walter Benjamin's understanding of the historical 'event'.