WARNING: The following contains spoilers for American Horror Story: Double Feature Episode 4, "Blood Buffet," which aired Wednesday on FX.

American Horror Story Season 10, Episode 4, “Blood Buffet,” lives up to its name by revealing the details about its primary mystery this season. The black pill that inspires amazing feats of creativity at the cost of an unquenchable bloodthirst has set the season’s hapless characters spiraling slowly out of control. Why they need the pill is obvious, though what it gives them isn’t necessarily what they think they’re getting. But the specifics have waited until now. With Double Feature shifting gears to a parallel storyline in just a few episodes, delaying the answers any longer might clash with the mid-season finale. Here’s a quick rundown on the specifics of the pill, based on the information provided in "Blood Buffet."

How Double Feature’s Black Pills Work

American Horror Story Double Feature - The Chemist

The black pills are a creation of the Chemist, a Harvard-educated pharmaceuticals genius who worked with the military to develop new means of stimulating the creative parts of the brain. Basically, it supercharges neurons in a person’s occipital lobe, where the Chemist claims that talented people have denser clusters than the untalented. It’s worth noting that the Chemist’s military connections likely provide a tie-in to the second half of the season, “Death Valley,” and further suggest some link between the pills and the storyline’s confirmed extraterrestrials.

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How the Black Pills Affect the Talented

American Horror Story Double Feature - Belle Noir with black pill

As Double Feature has made clear, talented people find themselves preternaturally inspired under the influence of the pill. Frustration and psychological issues like writer’s block fall away, and the affected person can accomplish brilliant work in a short amount of time. Harry Gardner, for instance, effortlessly writes several superb TV scripts that attract Oscar-winning talent, while his daughter Alma masters a challenging violin piece after struggling for weeks. Both Belle and Austin cite it as the source of their success as well, and even Mickey, the destitute hustler, suddenly completes a handful of must-read screenplays. If the skill is there, the pill will let it be expressed in its most perfect form.

However, the downside is steep, as Belle exemplifies in "Blood Buffet." The pill takes away certain chemicals in the body that can only be replenished by fresh human blood. With it comes an intense hunger that can only be abated for a short time. It also appears to give the users enhanced sensitivity to blood -- Belle claims she can smell it through people’s skin -- along with other possible side effects that the show hasn’t revealed yet. The hunger eases if the user stops taking the pills, but the creativity dries up as well, leaving them unable to practice their art at all.

RELATED: American Horror Story: Double Feature Unearths a Haunting Origin for Its Monsters

What Happens to the Untalented

TV American Horror Story - Double Feature

All of the aforementioned side effects occur if the taker has sufficient creativity to fire the occipital neurons in sufficient amounts. The effect is disastrous for those who don’t -- such as “Blood Buffet’s” unfortunate karaoke singer. Their hair falls out, their skin goes deathly pale, and they develop bodily tics that affect their movement. The bloodlust remains, as does copious vomiting and aggressive behavior. Their final form resembles that of Max Schreck in Nosferatu and a quiet nod to Stephen King’s Salem’s Lot, which featured similar vampires in a small New England town.

The catch is that one doesn’t know before taking the pill which path the effects will take. Either the talent is there, or it isn’t, and if it isn’t, the result is damnation. That adds a dark wrinkle not only to characters who have taken it and “passed the test” like Mickey but people who may be talented and refuse to take it like Karen. There are also people who may not be talented but are desperate enough to take a chance, like Doris Gardner. That will doubtless play a huge part as the first half of the split season approaches its conclusion.

Witness the origin of the black pills in American Horror Story: Double Feature. New episodes air each Wednesday at 10 p.m. ET on FX.

KEEP READING: AHS: Double Feature Episode 4, 'Blood Buffet,' Recap & Spoilers