Spoilers ahead for Stranger Things Season 4, Volume 1. Up until Stranger Things Season 4 premiered, the Netflix series had only introduced one of the other kids experimented on in the top-secret Hawkins National Laboratories besides Eleven. So it’s a surprise that in one of Season 4’s first scenes, viewers are shown several hospital gown-clad children — some telekinetically spinning tops, others playing chess — in the lab’s rainbow room in September 1979. Perhaps the reason they’d never been shown before, as fans soon learned, is that most of them were killed in a massacre later that day.
A young boy named Ten, who’s seen playing with a Magic 8 Ball, is introduced first after Dr. Brenner, aka Papa, enters the room and asks if he’s feeling “up for some more lessons.” Hooked up to a brain wave monitor, Ten is successfully able to see hidden pictures Brenner is drawing. Then, Brenner instructs him to “find” another doctor, who was in another room teaching Six to use his powers to move a block. Ten suddenly sees Six and the doctor both being killed — and soon meets the same grim fate.
Cut to Brenner awakening on the floor with blood on his face. As he makes his way through the lab, there is blood all over the walls, and it seems everyone, including his employees, have all been killed. Then he finds a blood-covered Eleven, breathing heavily in front of a smashed two-way mirror in the rainbow room. “What have you done,” he asks her in horror. Military officials also believe Eleven was the perpetrator, with Sullivan years later referring to her as “Brenner’s little pet,” who’d been trained in “remote assassinations.”
The premiere episode’s end credits listed the following children as all being in the lab at the time of the massacre: Two (Tristan Spohn), Three (Morgan Gao), Four (Sparrow Nicole), Five (Jessica Arden Napier), Six (De’Jon Watts), Seven (Lana Jean Turner), Nine (Chloe Adona), Ten (Christian Ganiere), Twelve (David Alexander Kaplan), Thirteen (Hendrix Yancey), Fourteen (Jeremiah Friedlander), Fifteen (Bentley Williams), Sixteen (Ethan Green), Seventeen (Oliver Green), and Eighteen (Olivia Sembra).
Other than Eleven, that only excludes One and Eight from the carnage. As viewers learned during Stranger Things 2, Eight, aka Kali Prasad, escaped from Hawkins Lab before the killings, later reuniting with Eleven on the outside. Though Eleven was playing with Eight the day her birth mother visited, Kali doesn’t otherwise appear in Volume 1 of Season 4. A “friendly orderly,” played by Jamie Campbell Bower, references her, however, mentioning to Eleven in one scene that “Eight was still here” the day her mother visited, a memory that she revisits while in Owens and Brenner’s sensory deprivation tank called Nina.
The same “orderly” also informed Eleven that, though Brenner had insisted the One never existed, he’d personally “spent years with” him in Hawkins Lab. When she asked what happened to One, he explained that the story “doesn’t have a happy ending,” but that he “was a lot like” Eleven. “Everything was hard for him,” he said. “Then, out of nowhere, he walked in here and it was like something had changed. And I asked him what’s different, and he said... He said he had figured it out. He had found his strength in a memory from his past — something that made him sad, but also angry.”
After all, Eleven wasn’t exactly popular in Hawkins Lab, but rather was bullied for what her “siblings” considered to be weakness. It seemed the most powerful of all the children was Two, who’d defeated everyone else in Brenner’s circle game. That was until Eleven used the orderly’s advice to overpower him and ultimately win the contest. “You shamed me today,” Two angrily told Eleven afterward. “I didn’t wanna hurt you. You are weak and pathetic. I was holding back.” Then, he and three of the other children attacked her with their powers, leaving her with a concussion. “Tell Papa we did this, we will kill you,” he threatened afterward.
Though Eleven claimed she had no memory of what happened, Brenner punished Two by using a shock collar. Afterward, the orderly warned Eleven that Two “and the others” were going to attempt to kill her, and helped her hatch an escape plan. In the process, however, the orderly revealed himself to be One. In fact, Brenner’s inability to control him was the reason all the other children were even “born” in the first place, as the scientist began the program to “recreate” One’s powers in a way that he could control.
To keep his powers at bay, Brenner — who was first alerted to One’s abilities by his mother, aka Victor Creel’s wife — implanted something called Soteria in his neck to both “weaken” him and track his whereabouts. He referred to himself as a “prisoner” at Hawkins Lab, though Eleven essentially “freed” him by telepathically removing the implant from his neck. One never made it outside of the lab’s walls, however, after Eleven eventually overpowered him and banished him to the Upside Down, where he transformed into Vecna.
Though it remains to be seen if Eleven has indeed regained her powers in the 1986 timeline, Season 4’s second volume will likely include a rematch, resulting in the end for another one of the Hawkins Lab kids.