In "Rappaccini's Daughter," Giovanni Guasconti witnesses the death of a small lizard after a drop of moisture falls from a gorgeous flower picked by Beatrice Rappaccini falls on it. He sees that there is something terrible about the flower and, thus, about Beatrice's nature, as she is revived rather than harmed by the flower's perfume. He says to himself, "Am I awake? Have I my senses? What is this being? -- beautiful, shall I call her? -- or inexpressibly terrible?" In "The Birthmark," Aylmer, a scientist, speaks to his beautiful wife, Georgiana, about her hand-shaped birthmark. He says to her,
[...] you came so nearly perfect from the hand of Nature that this slightest possible defect, which we hesitate whether to term a defect or a beauty, shocks me, as being the visible mark of earthly imperfection.
Whenever Georgiana turns pale, Aylmer watches the birthmark grow in "an almost fearful distinctness." Thus, both Aylmer and Giovanni recognize the beauty of the women they observe but are horribly affected by the thought of a flaw in this beautiful woman. It is as though they desire perfection in each woman and are unwilling to embrace mystery or nature, to trust in something larger than themselves or simply enjoy the love these women feel for them.
Eventually, both Giovanni and Aylmer attempt to rid these beautiful women of their perceived flaws. Aylmer tells Georgiana that he feels himself to be
[...] fully competent to render this dear cheek as faultless as its fellow; and then, most beloved, what will be my triumph when I shall have corrected what Nature left imperfect in her fairest work!
When Giovanni is offered an "antidote" to the "virulent poison" that runs through Beatrice's body, and has begun to pervade his own, he takes it. When he offers it to her, she demands that he give it to her but wait to see what happens to her before he drinks it himself. He believes that the liquid is "almost divine in its efficacy" and "distilled of blessed herbs." He believes he knows what is best for her, that he can change her nature, just as Aylmer believes of Georgiana, and both women are so horrified at the thought of continuing life as they are that they welcome the chance to be freed of their so-called flaws. Ultimately, both Beatrice and Georgiana die as a result of their lovers' inability to accept them.