The purpose of this article is to prove that Conan Doyle’s treatment of suspicion exemplifies the essential literary ambivalence of his text. On the one hand, Doyle provides Victorian readers with a comforting list of usual suspects that confirm stereotypes, and the text then works as a reassuring disciplinary structure, suspicion being a mechanical method of designating those who are always already known as “deviant.” Yet, such prejudiced “reflex” suspicion is exposed, and the text proves much less conservative than it seems—so that eventually, suspicion changes objects, and targets the narration itself. The final reduction to “the truth” is highly suspicious and reopens Doyle’s narrative regime of suspicion.