During the Paris Congress of 1889, Freud showed little interest in the presentations on hypnosis. This surprising attitude may have been due to a certain ambivalence on his part, related not only to the controversy that put him in opposition to Meynert, but also to the case of Mathilde. Freud mentioned this patient, who died of sulfonal intoxication, in his Irma dream associations. Documents that, until now, have not been published, reveal that Freud had treated her for years by hypnosis for melancholia and that after a manic decompensation, he was forced to have her committed to a private clinic. The patient records, partially reproduced, reveal information about her, her sickness, and the attempted treatments, as well as information about her relationship with Freud, towards whom she had developed a massive sexualized transfer psychosis that, at the time, was untreatable. Her death, in 1890, must have weighed heavily on him, and the Irma dream attests to prolonged after-effects.