“The Adaptive Ultimate,” a short story by Stanley G. Weinbaum, was first published in the November 1935 issue of Astounding Stories. A young biochemist, Dan Scott, researching fruit-fly adaptability, believes he has discovered a sort of cure-all serum. Itching to try it on a human subject, he pleads his case to the esteemed surgeon Dr. Herman Bach of Grand Mercy Hospital. Bach finds Scott a charity case, a woman named Kyra Zelas, who is mere hours from dying of tuberculosis. Injected with Scott’s adaptability serum, Zelas is cured. But that’s not all. The skinny woman from the streets becomes the glamorous title character, the “adaptive ultimate,” the most adaptable human being who ever lived. Her appearance changes, chameleon-like, depending on whether it’s day or night, whether she’s indoors or out; it changes, even, depending on whom she’s talking to, for Zelas aims to please. She’s virtually impervious to poisons or wounds, being so adaptable that she can heal herself immediately. And since one sign of human adaptability is the ability to change one’s environment, Zelas sets out to change her surroundings for maximum evolutionary benefit, stopping short of nothing to get her way. She lies, steals, even murders, and becomes one of the most powerful people in Washington, DC—the consort of a Cabinet secretary, John Callan—en route to her eventual goal of world domination. Meanwhile, Scott has fallen in love with her, perhaps for the usual reasons and perhaps because Zelas simply has adapted so well to his presence that he can’t help himself. Zelas claims to love him, too, but this might be the adaptability talking. At any rate, Scott can’t bring himself to kill Zelas, however world-threatening she may be. Instead, he and Bach put Zelas to sleep with carbon dioxide gas—since not even a highly adaptable creature, Scott explains, can live off its own waste products—and then Bach operates on her pineal gland to curtail her adaptive powers. The story ends with the operation an apparent success, as the unconscious Zelas, no longer glamorous, now looks as bedraggled as she did when brought to the hospital; to Scott, however, nothing has changed. “‘How beautiful she is!’ he whispered.... To his eyes, colored by love, she was still Kyra the magnificent” (Weinbaum 74).