WARNING: The following article contains spoilers for Stranger Things Season 3, streaming now on Netflix.
Calling the finale of Stranger Things' third season a seismic shift is a massive understatement. It intertwines the season's two primary threads: the secret Soviet facility deep beneath Starcourt Mall that's attempting to reopen the gate to the Upside Down, and the effort by the Mind Flayer to assemble an army using Billy (Dacre Montgomery) as his human avatar.
The eight episodes come to a head in "The Battle of Starcourt Mall," in which Chief Hopper (David Harbour), Joyce (Winona Ryder) and the wacky journalist Murray (Brett Gelman) infiltrate the Russian base to shut down the Key, the reactor used to open the portal between dimensions. That would effectively cut the mental link to the Mind Flayer's new gooey version of the Shadow Monster, thus destroying its body. However, it's easier said than done, and by the time the mission is complete, there are a couple of key casualties, changing the complexion of the series moving forward.
BILLY THE BRAVE
Jonathan (Charlie Heaton) and his team (codename: the Griswold Family) try to lure the multi-limbed Meat Monster away from the mall and its target, Eleven (Millie Bobby Brown). After the teens get separated, a badly injured and depowered Eleven hides with Mike (Finn Wolfhard) and Max (Sadie Sink), leaving the monster to pursue Jonathan's squad. As they're about to depart, however, Billy tries to ram them with his car, only for Steve (Joe Keery) and his Scoops Ahoy co-worker Robin (Maya Thurman-Hawke) to smash into him, allowing the others to escape. The creature then follows Jonathan's car, but just when we think their plan is working, it turns around and heads back to the mall.
That's because Billy sneaks in, takes out Max and Mike, and kidnaps Eleven for the monster to finally devour. In the nick of time, though, the group reunites and starts launching fireworks at the behemoth, which is made from the liquified remains of several townspeople (referred to as the Flayed by the kids). Despite the distraction, Billy is about to end Eleven's life, only to get caught up in a moment where she recollects a memory he held of his estranged mother. It's the result of Eleven's incursion into his mind earlier in the season, which culminated in the girl appealing to Billy's humanity, and reminding him how happy he was with his mother that day, surfing at a California beach. That breaks the Mind Flayer's hold on Billy, and, just as the creature tries to use its teeth-laced tongue to kill Eleven, Billy catches its tendril in mid-air, saving her.
However, the monster uses its lethal tentacles to impale a defiant Billy, finishing the job by bursting open his chest with its tongue. Despite his checkered past, Billy dies a hero. Right after his lifeless body drops to the ground, the monster also falls dead, but it's because of another key sacrifice made simultaneously.
HOPPER THE HEROIC
With Dustin (Gaten Matarazzo) guiding Team Bald Eagle through the Soviet facility, Murray sabotages the power room and sets off alarms. That creates a window of opportunity for Joyce and Hopper to invade the control room, using gunfire to scare the scientists. Thanks to Dustin's heartwarming rendition of the theme song from The Neverending Story, the duo obtains the keys to shut down the reactor. But just as they're about to do so, the Soviet hitman, Gregori, attacks, which leads to fight with Hopper on the edge of the platform.
A battered and bruised Joyce uses her belt so she can turn the two keys simultaneously, but she delaying shutting down the equipment, because Hopper is still in the chamber. The plan backfires when Hopper throws his enemy into the reactor, creating an energy barrier that puts him on the wrong side of the control room. He can't get back to Joyce, but he reassures her it's OK to turn the keys, which will destroy the reactor and seal the rift, but also trigger an explosion that will kill him. With no other choice, Joyce turns the keys, and the resulting explosion disintegrates the Russian scientists near the reactor, and seemingly Hopper as well.
The rift closes, causing the Meat Monster to collapse right after murdering Billy. A frantic Joyce searches, but there's no sign of Hopper, and she and Murray flee as Soviet soldiers rush in. Luckily, the U.S. cavalry arrives, led by Dr. Sam Owens (Paul Reiser), who took over the MKUltra project in Season 2. As everyone unites, Joyce is left heartbroken as she sees Eleven in tears, realizing her Hopper didn't survive the raid.
MOVING ON (LITERALLY), THREE MONTHS LATER
As she initially intended, Joyce decides to leave Hawkins with Jonathan and Will (Noah Schnapp), as the town has brought nothing but pain. However, now they're taking Eleven with them. She's distraught after reading a letter Hopper wrote in which he relates how much he loves her. He only wanted for her to be a normal girl, which is pretty intriguing, given that after a bite from the Meat Monster, Eleven's powers are now barely working. Nevertheless, she's powering through and trying to remain optimistic. She admits that she loves Mike, and promises to return to Hawkins for Thanksgiving and Christmas.
All of the teens are seen going through the motions, hugging and crying, with lovers Jonathan and Nancy also saying their farewells. When the Byers eventually leave with Eleven, the dust settles, and Mike goes home to be consoled by his mother; Max is in her room mourning Billy; Lucas and Dustin give Erica a box of Will's discarded Dungeons & Dragons books, acknowledging her inherent nerdiness, and unofficially inducting her into the gang; and, Steve and Robin, jobless after the closing of Starcourt Mall, land jobs at a video store.
RUSSIA'S HOLDING NEW SECRETS
It's clear the battle of world powers over the Upside Down will continue, as the post-credits scene shows the base in Kamchatka, Russia, where Season 3 began. There, the Soviets attempted to open a gate to the Upside Down, but repeated failures drove them to Hawkins. Now, we witness a Russian prisoner being fed to a Demodog, but not before the Soviets decided against dragging "the American" from his cell.
Fans, of course, hope "the American" is Hopper, who somehow survived the explosions. Seeing as Erica found a Demodog cage beneath Starcourt Mall, and Dustin found an electric prod used to fend off the creatures, it would appear the Demodog was extracted in America early on and then transported to Russia. It could also means there are more beasts from the Upside Down in these Soviet cells.
Other theorists think Hopper might have been pulled into the Upside Down, as the explosion did disintegrate scientists into goo. That could hint the Russians might have finally perfected access to the doorway in Kamchatka, where they extracted Hopper. Either way, you can be certain Russia will keep probing, with the Duffer brothers keeping all cards close to chest until Season 4.
Created by the Duffer Brothers, Stranger Things stars Winona Ryder, David Harbour, Finn Wolfhard, Millie Bobby Brown, Gaten Matarazzo, Caleb McLaughlin, Noah Schnapp, Natalia Dyer, Charlie Heaton, Joe Keery, Priah Ferguson, Cary Elwes, Jake Busey and Maya Thurman-Hawke.