In season 4 of Stranger Things, nine months have passed since the Mind Flayer’s defeat
at the Starcourt Mall. Eleven has moved with the Byers family to California,
forcing her and Mike into a strained long distance relationship. Mike and Dustin also begin to have
a strained relationship with Lucas and Max. Lucas has joined the high school basketball
team and befriended the popular jocks, led by Jason, while Max has pulled away from
everyone as she continues to grieve the death of Billy. Mike and Dustin join the Hellfire Club,
the school’s Dungeons and Dragons club, which is led by the eccentric outcast Eddie Munson.
When Jason’s cheerleader girlfriend Chrissy is plagued with headaches and nightmarish visions,
she pays Eddie a visit to buy drugs to cope with her symptoms. While in Eddie’s trailer,
Chrissy becomes possessed by an evil force from the Upside Down, which brutally murders her.
When Chrissy’s body is found, Eddie goes on the run, as he becomes the police’s prime suspect.
Jason and his gang of bully jocks lead the charge in labeling Eddie and the Hellfire Club a group
of satanic devil worshippers responsible for Chrissy’s death and attempt to find Eddie to enact
vigilante justice. As Mike departs Hawkins to spend his Spring Break with Eleven in California,
Dustin, Max, and Lucas team up with Nancy, Steve, and Robin to uncover the truth behind Chrissy’s
murder. The group explains to Eddie their previous experiences with the Upside Down and name this new
evil threat Vecna, who continues to possess and murder high school students.
Nancy and Robin follow a lead to the Pennhurst psychiatric institution where they interview a
man named Victor Creel, who had been imprisoned decades prior for murdering his family. Victor
explains to them that after his wife and young children moved into their new home in Hawkins,
they experienced similar horrific visions as Chrissy before being possessed and killed.
Victor was arrested for the deaths after no one believed his story.
Nancy also figures out from Victor’s story that hearing
his favorite song was what pulled him out of Vecna’s possession and saved his life.
Meanwhile, Max discovers that all of Vecna’s victims experienced severe headaches and
nosebleeds, and were suffering from PTSD from past traumas. The same symptoms Max
was currently experiencing. And that’s when Max realized that Vecna was possessing her
as well. Fearing Vecna could kill her at any moment, Max writes letters to all of her friends,
then heads to Billy’s grave to read him a letter. At the gravesite, Max is possessed
and taken to Vecna’s altar in the Upside Down where he prepares to kill her. Nancy and Robin
manage to relay to the others that music can break Vecna’s possession, and they play Max’s
favorite song to her. This helps Max fight Vecna off and escape the Upside Down, saving her life.
Dustin theorizes that new gates to the Upside Down were being opened at the sites of Vecna’s murders.
When Steve investigates the bottom of Lover’s Lake to confirm Dustin’s theory, he is pulled into the
Upside Down and attacked by bat-like creatures. Nancy, Robin, and Eddie enter the Upside Down
to save Steve, but are unable to return through the gate due to it being guarded by more of the
creatures. And so, the group decides to make their way through the Upside Down to Eddie’s trailer
to find another exit. Back in the real Hawkins, as the police begin to investigate the Hellfire
Club for their involvement with Eddie, Dustin, Max, Lucas, and Lucas’ sister Erica flee the cops
and their parents to head to Eddie’s trailer and save their friends. They manage to save
Robin and Eddie from the Upside Down, but before Nancy escapes, she becomes possessed by Vecna.
Meanwhile, Mike arrives in California to spend his spring break with Eleven and the Byers family.
He quickly discovers that although Eleven had told him she was doing great, she was actually
depressed and mercilessly bullied. Eleven was also upset with Mike for not telling her he loved her.
Will had his own issues with Mike, feeling abandoned by his best friend who only seemed
to care about Eleven. And Jonathan was dealing with his own relational issues,
too afraid to tell Nancy that he was having second thoughts about their college plans,
wanting to stay close to protect his family.
The kids quickly have the house to themselves, as Joyce receives a message from Hopper,
revealed to have survived the Starcourt Mall explosion and was currently imprisoned in Russia.
A kindly prison guard named Antonov agrees to help Hopper escape, and tells Joyce to
bring $40,000 to a Russian pilot in Alaska. Joyce teams up with Murray Beauman to head to Alaska,
where they meet the eccentric pilot, Yuri. Yuri betrays them, drugging Joyce and Murray, ratting
out Antonov to the other Russians, and thwarting Hopper’s escape attempt. As Yuri flies a captured
Joyce and Murray to turn over to the Russians, they escape their binds and Murray uses his new
black belt skills to subdue Yuri. They hatch a plan to break Hopper out of prison, with Murray
posing as Yuri to deliver Joyce and the real Yuri to the Russians. The plan works, and the group are
allowed to enter the prison, where they are taken to watch Hopper, Antonov and a group of prisoners
fight a demogorgon. Hopper uses his prior experiences with the creature to save his
and Antonov’s lives, while Murray and Joyce reveal their ruse, subduing the guards and unlocking the
doors to allow Hopper and Antonov to escape. Hopper and Joyce have an emotional reunion,
but they were still stuck in a Russian prison with a loose demogorgon, with no discernible way home.
Back in California, after her bullies publicly humiliate her, Eleven finally snaps and assaults
one of them. After being arrested, Eleven is saved by Dr. Owens, who warns her of everything that
was happening back in Hawkins. While higher ups in the government believe Eleven could
be responsible and was too dangerous, Owens assures her that he believes she was good,
and had been working on a program that could give her her powers back. Eleven agrees to go
with Owens to attempt to restore her powers and save Hawkins from Vecna, while two of Owens’ men
are tasked with protecting Mike, Will, and Jonathan. When armed soldiers attack the
Byers’ house, the boys flee with Jonathan’s stoner friend Argyle and race to find Owens and Eleven.
Owens takes Eleven to a secret underground lab where he reveals that he has been working with a
very much alive Dr. Brenner to develop an isolation tank known as NINA that would
allow Eleven to access her forgotten memories and reawaken her powers. Inside NINA, Eleven remembers
her time in Hawkins Labs under the care of Dr. Brenner, where she was bullied by her
fellow superpowered experiments. Eleven had been befriended by a kind orderly, who warned Eleven
that Brenner wasn’t to be trusted. Eventually, the orderly revealed himself to be One, the
first child experimented on by Brenner, who had a device in his neck that suppressed his powers.
Eleven helped remove the device to allow them both to escape, but the orderly instead massacred
everyone in the lab. It turned out, the orderly was actually Henry Creel, the son of Victor Creel.
He had used his psychic abilities to murder his mother and sister, and though Victor was told
Henry died, he was actually placed in the care of Brenner. And now that Eleven knew his villainous
secret, he was going to kill her too. Eleven managed to overpower Henry, ripping open the
first portal to the Upside Down and sending Henry through it, where he was transformed into Vecna.