Este segundo relato es el más largo de los tres, y el más pesado también debido a que casi no hay ningún diálogo en el sentido de que Dupin realiza su larguísimo análisis casi sin interrupciones por parte de su amigo anónimo. No obstante, este está hecho con una gran precisión y rigurosidad lógica, que constituye el principal deleite de las tres historias de Dupin, y considero que las expectativas que se tengan previo a leer este cuento influirán enormemente sobre si es tedioso o interesante, aunque sí es el menos interesante de releer de los tres, puesto que el suspenso de cuáles serán las conclusiones siempre son un buen factor que mantiene la atención del lector por períodos largos.

This is the second case of the three stories in which appears Edgar Allan Poe’s C. Auguste Dupin. Written about a year after the first one, in the fictional universe two years have passed since the investigation of the murders in the rue Morgue and about a year after the publication of such investigation by the anonymous protagonist friend of Dupin. The narrator talks about how, after Dupin had solved the murders of the rue Morgue without really explaining how he had done it, he had become famous among the police forces and they would try to get his help in more cases.

In the specific case around which revolves this story, the prefect of police G. makes an unspecified economic agreement with Dupin regarding the reward it has been offered for solving the case to get his help. Later, the narrator gathers all of the journals and police reports about the murder of Marie Roget, and after he and Dupin had read them, the latter begins his analysis comparing how ordinary is this case while the case of the rue Morgue was extraordinary; then, concentrating on the case itself, he starts by making sure of the corpse’s identity (something some journals were doubting about) simply by his knowledge and analytical abilities.
  Also, Dupin conducts a more thorough search inside the journals to look for collateral facts without any apparent relation with the case that might have been overlooked. With his findings (irrelevant ones on his friend’s first look) the chevalier continues to unravel the mystery to the point in which it becomes necessary for him and his friend to go into action to identify their suspect by his name. After this point in the tale, it is only mentioned that they succeeded and that prefect G. kept his end of the bargain. Then, the narrator closes the curtain by going back to that with which he had started, the calculation of probabilities and the coincidences, a fundamental knowledge in Dupin’s analysis.

Something remarkable about this story is how and why it was created. Wirh it, Poe attempts to solve a real case, that of Mary Cecilia Rogers, murdered in New Yorks outskirts, which remained unsolved when Poe wrote this tale; and he wrote it following the essential facts of the real case and establishing parallels for the rest, and with no more information than what Poe was able to gather from journals. And in the ending note of the tale it is said:

...the confessions of two persons, (one of them the Madame Deluc of the narrative) made, at different periods, long subsequent to the publication, confirmed, in full, not only the general conclusion, but absolutely all the chief hypothetical details by which that conclusion was attained.

_Wikisource

This second tale is the longest of the three, and also the heaviest because there is almost no dialogue since Dupin does his very long analysis almost without interruptions from his friend. Nonetheless, the analysis is done with a great rigorous and precise logic, which constitutes the main appeal in all of Dupin’s stories. Besides, I believe that the expectations one has before reading this tale are a key factor in how much it will be enjoyed, although it is certainly the least interesting to reread of the three due to the fact that the suspense about what will be the conclusions is an important factor to keep the reader’s attention throughout the long analysis.