According to one fan theory on Reddit, the AHS: Double Feature trailer already shows Doris after she’s taken the black pill. There’s a shot in the trailer of one of the talentless pale creatures standing in a graveyard. The theory claims this pale creature is Doris and that she turns into this creature because unlike her husband and daughter, she doesn’t have any talent.
Austin already explained on the show that the wild vampire-like creatures in town who feed on dead animals are people who took the black pills. But instead of helping them reach their full potential, the pill turns them into these pale creatures because they don’t have true talent.
Alma accuses Doris of being talentless as an interior designer after she struggles to decorate the house they’re staying in… Some fans think this could have been foreshadowing.
The Redditor who shared their theory wrote that, because Doris “would do anything to be with them, to be like them, to be a family again,” she takes the pills like her husband and daughter did.
The theory also claims that Doris might kill her baby in the process. That opens up a whole other aspect of the theory, especially since, if Doris takes the pill, it’s unclear if she does it before or after she gives birth.
Source : https://www.distractify.com/p/what-will-happen-if-doris-takes-the-pill-ahs