As the final episode opens, Murray and Dmitri, who fled from the Russian prison, are monitoring Yuri as he fixes (or pretends to fix) the chopper, which is their sole method of returning to the United States. Unbeknownst to anybody else, Yuri sabotages the repair work since he still has KGB money on the back of his mind and has no intention of aiding the Americans. Joyce and Hopper are tidying up and changing into warmer attire inside the tiny church. When Joyce sneaks a peek at Hopper, she notices his horrifically scarred back, which is proof of the violence he experienced while incarcerated. When she questions him about it, he bemoans the fact that he should never have put her life in danger by sending her a message in the first place.
Hopper informs the others that he finally got a call back from a Dr. Owens-related person and that he now knows that El left the lab and is now with Joyce’s children. He is disappointed that they will never reach Hawkins in time to assist them. But, they remember that all creatures from the Upside Down are interconnected. So, harming one causes harm to all. Hopper leads the team back to the prison/research facility in order kill as many of the creatures as possible, which might give the kids in Hawkins an advantage.
Joyce, Hopper, and Murray return to the prison as Dmitri stays behind with Yuri to try and persuade him to fix the helicopter and truly assist everyone.
The trio makes it back to the prison and finds everyone dead at the hands of the creatures, including many that were held in stasis in a lab. But, they hatch a plan to lure them all into the prison yard and use a flamethrower to destroy them all.
Back in Hawkins, Nancy and Steve lead a team back into the Upside Down, hoping to catch Vecna off-guard and kill him while he is distracted by Max, who plans to act as bait back in the real world.
Meanwhile, El realizes her team can’t make it back to Hawkins in time, so she plans to psychically connect with Max and fight Vecna from inside her mind.
The plans immediately go awry as Nancy, Steve, and Robin are quickly caught by Vecna’s tentacles as they sneak toward his lair. Eddie and Dustin are trapped by the bat creatures, who they lured away from Vecna’s house. Max is unable to protect herself from Vecna and begins to succumb to his mental powers. El tracks down Max in time to fight Vecna, but he captures her as well, making her watch as he invades Max’s mind.
In Russia, Hopper, Joyce, and Murray are successful in killing all the creatures and Yuri comes through and fixes the helicopter to take them all home to the U.S.
El finds the strength to break free of Vecna’s power and is able to take control of him in Max’s mind. This also frees Nancy, Steve, and Robin, who are able to burn Vecna’s body to a crisp in the Upside Down. As Vecna is dying, he tells El that he has already won, they just don’t know it yet.
We flash to Hawkins where huge fissures in the earth form at the site of each Vecna murder (now including Max, who died before El possibly saved her) and flow toward each other. Much of the town is destroyed. Fast forward a few days and we see that the media has claimed a giant earthquake hit Hawkins and many residents are leaving as El, Mike, Will, and Jonathan arrive. They learn that Max survived, but is in a coma.
The team plans to hide El back at Hopper’s cabin, which has largely fallen down. As they are cleaning it up, Hopper arrives with Joyce for a reunion with the boys and El.
As the episode wraps up, Will says he still feels Vecna’s presence and the air in Hawkins is filled with ash, as what appear to be volcanos have opened up along the lines of the fissures. So much for happy endings ahead of the final season 5 coming next year!
