This chapter investigates the little-known Spanish translation of Edgar Allan Poe’s “The Murders in the Rue Morgue” by the elusive J. de Granada, first published in the Madrid newspaper El Clamor Público in 1858. Through close comparison of Poe’s original text, Charles Baudelaire’s French version, and J. de Granada’s rendering, the study demonstrates that the Spanish translator relied significantly on Baudelaire’s linguistic and stylistic choices, creating a “Frenchified” translation rather than working exclusively from Poe’s English text. The analysis further illustrates how J. de Granada’s partial Hispanicization of character names, locations, and specific lexical items reveals an attempt to adapt the narrative to Spanish cultural expectations, thereby establishing this version as a retranslation situated at the intersection of French and Spanish literary practices. By aligning these findings with Poe’s own thematic emphasis on interpretation and the deciphering of meaning, the chapter argues that the act of translating, like Dupin’s ratiocination, functions as a process of uncovering deeper truths buried within linguistic and cultural layers. In underlining J. de Granada’s role as both a transmitter and creative mediator, the chapter repositions this neglected translation as a significant contribution to the early Spanish reception of Poe’s work. It thereby calls for broader recognition of nineteenth-century translators’ interpretive authority and the transnational dialogues fostered by their endeavors.