What exactly is thiopental sodium in Pluribus Episode 4? Details about the mysterious drug, revealed

Pluribus Season 1, Episode 4, Please, Carol, came out on November 21, 2025, on Apple TV+.

The show was created by Vince Gilligan. It revolves around Carol Sturka (played by Rhea Seehorn). She is one of the few people in the world who cannot be taken over by an alien “joining”, while all humanity has become part of a hive mind called the Others.

Pluribus Season 1 has 9 episodes. In Episode 4, Carol wants to understand this so-called Joining and maybe stop it. However, she steps into danger. She steals a drug called thiopental sodium from a hospital. This drug is like a truth serum, which she first tries on herself. Then she uses it on Zosia to find out if the Joining can be reversed.

Now, many viewers are wondering: What is thiopental sodium? Why did Carol use it? Is it realistic?

---

What is thiopental sodium that Carol uses in Pluribus Episode 4?

Thiopental sodium (also known as sodium thiopental or Pentothal) is a type of medication classified as a barbiturate. It works as a rapid anesthetic and is usually given through a needle into a vein.

In real life, it can cause a person to fall unconscious in a few seconds by slowing down the brain and nervous system. Its effects wear off quickly, but some of the drug stays in the body’s fat tissues for a while.

In Pluribus Episode 4, Carol employs thiopental as the main drug due to its rapid action of making people unconscious, thereby facilitating her attempts to elicit answers. During the episode, Carol surreptitiously injects a vial of thiopental sodium stolen from a laboratory in the hospital. To avoid raising any suspicion, she stages a scene where she claims that she needs heroin.

Carol first tries the drug on herself at home and films herself to check its aftereffects. While under the drug, she cries about her late wife, shows her hidden feelings, and even admits she likes Zosia.

After watching the video, Carol sees that the drug makes people tell the truth and lose their inhibitions. She goes back to the hospital and gives the drug to Zosia through her IV. She just wants to know: Can the Joining be reversed?

However, things go wrong. Zosia falls under the drug, and “Others” from the hive-mind appear, chanting “Please, Carol.” They are not angry, but sad and pleading, as if they feel hurt by what Carol is doing.

Then, things go downhill. Zosia is already weak from an earlier injury and strong emotions. She collapses and has a heart attack.

The “Others” immediately react. They break the handcuffs Carol had used to stay attached to Zosia and try to help her. It is unclear if Zosia survives. Pluribus Episode 4 ends with sadness, guilt, broken trust, and, of course, a cliffhanger.

This scene is not just about physical danger. It is also about right and wrong. In her quest for the truth, Carol may have damaged the trust between herself and the Others instead of gaining control. Critics argue that the incident demonstrates the risky nature of imposed honesty and brings up the issues of choice, consent, and the price of revealing truths.

---

What to expect in Pluribus Episode 5?

Considering the way Episode 4 wraps up, it is very probable that in Pluribus Episode 5, we will get to see the fallout of Carol’s experiment.

Trust issues with the others: The “Others” repeating “Please, Carol” reflects their loyalty but also their pain. Carol’s deed may result in the loss of their trust. The Others might either avoid Carol or be much more cautious in their interactions with her in Episode 5, thus making it all the more difficult for her to extract the information she needs.

Zosia’s destiny: Zosia’s survival is uncertain in Pluribus. In the event of her survival, her bond with Carol would indeed be very different; it would be characterized by guilt, fear, and mistrust. If she dies, Carol would endure the loss, as well as the moral ramifications of endangering someone’s life merely for the sake of attempting to reverse the “Joining.”

Carol’s internal conflict: The use of thiopental is not merely about getting answers but rather a very intimate matter. Carol is well aware that she has drugged Zosia and has betrayed the trust. She may have a hard time deciding on her course of action. Will she continue to take risks no matter how dangerous and wrong they may be? Or will this make her reconsider her strategy?

Other immunes & new allies: Pluribus Episode 4 also shows Manousos Oviedo, another person immune to the Joining. He lives alone, so he could help Carol. Episode 5 might show his side, whether he trusts the hive, and if he will work with Carol or do his own thing.

Big questions like ethics: Pluribus may also ask bigger questions. Should Carol try to reverse the Joining? The hive-mind is emotional, connected, and caring. By betraying them, Carol might hurt the very community she is trying to help. This raises a difficult question: what does it really mean to “save humanity” if it hurts others?