After the Rue Morgue´s case, Dupin became popular in the police, by his analitic skill, he at the same time help them to solve many cases, which the most prominent was these, the Marie Roget´s case.
She was a young who became popular in the population since she help to impulse an important brand of perfumes, besides that for her unquestioned beauty. The mistery begin since she dissapear for a week, without notices of her, neither the family nor friends start to worry about her, who reappear a week later, with a sadden aspect, nobody put some attention to the subject, so the regular life it pass by.
Five months later the young dissapear again, and four days later her body is discovered floating in a river. When her ex-fiance is inform about so grave notice, he kill himself. The authorities start the investigation, and after weeks of don´t have information (after tried everything including an extraordinary reward), call for Dupin, and expect than his wise ingenuity can solve this case.
So in effect Dupin and our character start to investigate the case, soon have very right conclusions, the same which not even the police could have notice, be based on the papers has published about the case. The history ends when our characters decide to go to the crime scene, to reconstruct the facts in order to known a more correct right, This history doesn´t have a concrete end. Poe narrates everything with many caution, with the suspicious characters, however he leave the end to the imagination´s reader, since this novel was inspired in a real murderer, in which at that time the criminal hasn´t been exposed, The author prefer not to ended it, nevertheless he conclude that the key to known a truth, is in the most minimum details.