Hopper and Eleven head for the lab, where they find the gate guarded by Demodogs.
Jonathan, Nancy, and Joyce take Will to Hopper's cabin and overheat him to force the Mind Flayer out.
Mike, Dustin, Lucas, and Max want to draw the Demodogs away from the gate, but Steve keeps them at the house for their own safety. Billy, forced by his abusive father to look for Max, arrives at the Byers house. He starts a fight with Steve, but Max sedates him, and the group leaves in Billy's car. They start a fire in the tunnels, but Dart blocks their return. Dustin feeds Dart a "3 Musketeers" bar, and Dart allows them to pass.
Eleven channels her anger into closing the gate, and as the gate closes, the remaining monsters in Hawkins die.
One month later, Hawkins Lab has shut down. Barb is given a funeral, and Owens provides Hopper with a birth certificate for Eleven. The students attend the school's winter dance, the Snow Ball. Max and Lucas kiss, as do Mike and Eleven. Nancy pities Dustin and dances with him. In the Upside Down, the Mind Flayer towers over the school.
This episode provides examples of:
- Actually Pretty Funny: After applying a tourniquet to Dr. Owens' clearly very badly mangled leg, Hopper says "Don't go anywhere." Owens manages a weak but appreciative little chuckle in response.
- Almost Kiss: Hopper is having none of this kissing business between Mike and Eleven.
- Alone Among the Couples: Dustin at the dance, until Nancy steps in to dance with him.
- Androcles' Lion: Dustin taking care of the Demo-dog D'Artagnan when it was small allowed him and his friends some good will when trying to defeat the Eldritch Abomination from The Upsidedown. When they meet each other again, Dart willingly lets them pass after being offered the candy it likes, letting the Party escape unscathed.
- Beam-O-War: During the Final Battle, Eleven uses her telekinesis to block what looks like another smoke/infection attack coming from the Eldritch Abomination.
- Berserker Tears: Mike breaks into tears while wailing on Hopper for not telling him Eleven was alive.
- Big Damn Hug: Eleven and Mike share one when they're finally reunited, which is shortly followed by Eleven sharing an emotional group hug with Lucas and Dustin.
- Big Damn Reunion: Between Eleven and Mike, of course. Soon after, Eleven with the rest of the boys as well as with Hopper and Joyce. Subverted for Max, since she had only just met El.
- Bittersweet Ending: Will is cured of the virus and Eleven is able to close the Gate to the Upside-Down, ending the Mind Flayer's attempt to invade our reality. Nancy's exposure of the Lab's role in Barbara's death, if not the exact circumstances, forces the government to shut down the Lab and the experiments within, allowing the Hollands closure. Max is finally able to stand up to Billy and make him leave her and the boys alone, while starting a relationship with Lucas, which Dustin accepts. Dr. Owens is able to procure a fake birth certificate for Eleven as "Jane Hopper", allowing her a chance to live a normal life and be with Mike. However, Bob and a lot of (mostly) innocent people were killed at the Lab when the Demodogs overran the compound, leaving Joyce in mourning. While Steve has accepted Nancy is with Jonathan, he's still not fully over her. Also, Kali is still out there, and wants her sister back. It's also implied that Owens went behind his superiors' backs to get the forged documents for Eleven, meaning that they may come for her if they find out. There's also the possibility that Brenner is still alive. Worst of all, while confined to the Upside-Down, the Mind Flayer is still alive, and clearly out for revenge against the Party.
- Blade Reflection: Hopper uses his blade to spy on the demodogs from around a corner near the entrance of the gate.
- Bookends:
- The scene of Dustin looking for his hairspray mirrors his search for quarters in the season premiere.
- Mike suffering through Karen taking pictures of him echoes his Halloween night in the second episode of the season.
- Boom, Headshot!: Hopper deals with the Demodogs this way after shooting one in the face.
- Calling the Old Man Out: Mike has a massive breakdown over Hopper hiding Eleven from them for a whole year, becoming so enraged Mike actually attacks the older man. Hopper takes it in strides, even when Mike punches him, and consoles Mike when the boy calms down.
- Career-Ending Injury: Discussed in the epilogue. When Hopper asks about his leg, Dr. Owens jokingly notes that his football career may be over.
- The Chain of Harm: A quite visual example. Billy's father takes his anger out on Billy by pushing him aginst a wall. When Billy finds Max, he does the same with her.
- Continuity Nod:
- Dustin using the Farrah Fawcett spray, as recommended by Steve.
- At the dance, Nancy tells one of the boys the punch is "pure fuel."
- Convenient Slow Dance: They didn't include a school dance for nothing.
- Curb-Stomp Battle: Steve vs. Billy. They are roughly the same height, but Billy is much stronger and crazier. Steve gets a few good hits in, but Billy positively mashes Steve's face (it also helps that Billy fights dirty, and bashes Steve's head with a plate to stun him). Steve ends up knocked unconscious, and takes a while to properly wake up.
- Dance Party Ending: This season ends with all of the kids dancing at the Snow Ball.
- Delicious Distraction: Dustin distracts Dart with some "3 Musketeers" bars allowing the group to sneak past. Justified, as Dart was fed a diet of the stuff as it grew, and it remembers Dustin enough to be content with eating it instead of viciously mauling them like other Demodogs.
- Did You Just Flip Off Cthulhu?: When they are trying to force the Mind Flayer out of Will, Joyce flat out demands the Eldritch Abomination leave her son.
- Does This Remind You of Anything?: The way the virus is driven out of Will is reminiscent of the practice of exorcism.
- The Dog Bites Back: After Max drugs Billy with anesthesia, she threatens to smash his groin with Steve's spiked bat if he doesn't back off. He acquiesces just before passing out.
- Dramatic Slip: While running across the tunnel to safety Mike slips and falls. A vine immediately grabs on to his ankle and tries to drag him away but his friends return to rescue him.
- Drone of Dread: Drone sounds play when Hopper and Eleven descend on the elevator to the rift.
- Dude Looks Like a Lady: When Steve regains consciousness, he briefly mistakes Mike for his sister Nancy.
- Earn Your Happy Ending: While the series isn't over, the finale nonetheless has this moment for Eleven and Mike. After everything they've been through — fleeing government agents, fighting a monster from another dimension, Eleven being momentarily lost in the Upside Down afterwards and then being kept away from Mike to hide her from the government for nearly an entire year, and then facing down a horrific Eldritch Abomination attempting to break through into Hawkins — they finally get to have their dance at the Snow Ball, topped off with a Big Damn Kiss. Earn Your Happy Ending indeed.
- The End... Or Is It?: The final shot shows the Mind Flayer looming over the Upside-Down version of Hawkins Middle School where most of the characters are assembled, showing that it hasn't given up or forgotten who foiled it.
- "Eureka!" Moment: Joyce remembering how Will mentioned the Mind Flayer doesn't like heat makes her and the others realize how they can drive it out of Will's body.
- Evil Is Deathly Cold: Exploited. Joyce remembers that the Mind Flayer despises heat, and realizes that this is the key to getting it out of Will's body - bringing him to Hopper's cabin, and then making it all heated up so that the Mind Flayer is driven out. They turn it up once he awakens and starts freaking out, a sign that the Mind Flayer is indeed affected by their plan.
- Failed a Spot Check: Billy shows up at the Byers house, finds Steve and the kids and assumes it's some creepy sleepover. Keeping in mind Billy is a bit messed in the head to begin with, he barges into the house and fails to notice the Room Full of Crazy that has become the whole house or understand what the situation is really about due to also being Locked Out of the Loop. Where he really fails the check is in regards to his sister with the syringe that puts him out.
- Flipping the Bird: As Bauman lazily - and gleefully! - waves a salute to the soldiers leaving the locked down Lab, one MP flips him the bird without so much as looking in his direction.
- Foreboding Fleeing Flock: Inverted, when a large group of demodogs runs past Dustin and Steve without attacking, everybody realizes that the Mind Flayer is sending them after Eleven.
- Freaky Is Cool: The girl who asks "Zombie Boy" Will to dance seems to think so, just as Jonathan claimed earlier in the season.
- Get Out!: Steve demands this of Billy. The latter is not willing to comply so a fight scene ensues.
- Groin Attack: How Billy takes out Steve during their first bout. It's also one of the few things that Billy seems to be vulnerable to. Lucas manages to temporarily stun Billy by kneeing his nuts when the latter attacks him.
- Group Hug:
- Eleven gives one to Lucas and Dustin when she reunites with them.
- A three-way hug between Will, Joyce and Jonathan after they manage to drive the virus out of Will's system.
- Handshake Refusal: Max offers to shake Eleven's hand after introducing herself, only for the latter to walk right past her without so much as a reply.
- Happily Adopted: What Owens sets up for Hopper and Eleven as a way of thanking them for sealing the gate (which his team had been unable to do).
- Hard Head: Steve is back in fighting form remarkably soon after Billy gives him a concussion.
- Headbutt of Love: Mike and El after their kiss on the dance floor.
- High-School Dance: A Call-Back to the last episode of season 1, where Mike asked Eleven to go with him to the "Snow Ball". In this episode they finally do.
- I Can't Dance: At the "Snow Ball," Mike invites El to dance. She agrees, but it turns out neither of them know how. Mike assures her they'll learn together.
- Idiot Ball: Quick tip for the kids: if you're trying to avoid someone and they're right outside the house, don't openly stare out the window. Steve could have persuaded Billy that the kids weren't there had Billy not seen them; instead, Billy sees them and forces his way in, leading to the No-Holds-Barred Beatdown discussed below.
- Impairment Shot: The camera takes Billy's blurry point of view after he gets sedated by Max.
- I Need a Freaking Drink: "Sandwich" substituted for "Drink"; Hopper initially refuses to share Dr. Owens' sandwich as he's on a diet, but then he finds out that he should keep Eleven out of sight for another year. Knowing how Eleven and Mike will respond to that, Hopper grabs the other half and chows down without a word.
- Interrupted Bath: Mike's mom is enjoying a relaxing bath when the doorbell rings.
- Ironic Echo:
- Right before Billy knocks Steve down, he reminds him to "plant his feet".
- At the school dance:Boy: What's in this?
Nancy: Pure fuel.
- Keystone Army: While the Mind Flayer isn't dead, when the breach is closed it loses its power over this world and all the creatures it was controlling die.
- Kids Are Cruel: At the School Dance, Dustin's attempts to rebound off of being the Romantic Runner-Up with Max don't exactly end well, leaving him sitting by himself and nearly in tears. Luckily, Nancy, who was chaperoning, offers to dance with him.
- Kids Driving Cars: Steve (18) was knocked unconscious from his fight with Billy. Since he was the only one in the group old enough to drive, Max (13) ends up driving everyone to the pumpkin patch. Needless to say, she doesn't kill anyone, but Steve is very alarmed when he wakes up to find an eighth-grader driving the car.
- Laughing Mad: Billy comes completely unhinged during his fight with Steve, revealing just how deranged he really is.
- Lightning Reveal: The Mind Flayer in the last scene is fully revealed when the lightning strikes.
- Longing Look: Steve shoots one in Nancy's direction upon dropping Dustin off at the Snow Ball.
- Meaningful Look: On their Climactic Elevator Ride down to the Hellgate, Eleven grabs Hopper's hand and both share a meaningful look before the former starts her mission to seal the gate shut.
- Mirror Monologue: Lucas's Annoying Younger Sibling catches him preparing his pick-up lines in front of a mirror.
- Monster Threat Expiration: Downplayed. Hopper is able to use firearms to hold off the demodogs, which previously barely noticed bullets. Admittedly he's just causing them to lose balance so they fall, the bullets still don't seem to penetrate. However, his shotgun blasts are visibly shown exploding one of the Demodogs' heads. It's possible that since they are juvenile, they have yet to grow the extremely thick skin of a "proper" demogorgon. It's also possible that a shotgun at close range can hurt Demogorgons/Demodogs due to being a much larger caliber with far more stopping power than the pistols and sub-machine guns that were previously used, and that headshots work much better than body shots, especially given the fleshy faces of the creatures.
- Mum Looks Like a Sister: Billy compliments Mike's mother on her youthful look by telling her that he didn't know Nancy had a sister. An awkward flirting scene ensues.
- Must Make Amends: Eleven feels a strong urge to close the gate as she knew she was responsible for opening it in the first place.
- My God, What Have I Done?: Seeing Mike break so completely that he attacks Hopper makes the older man realize just what Mike was going through while El was with him, to the point that Hop can only let Mike get it out of his system and apologize.
- Near-Miss Groin Attack: When Billy confronts the group at one point and gets too physical with them that he beats up Steve and pushes Lucas into a shelf. Max stops him by injecting him with a syringe full of sedatives, then threatens him to never harm them again by using a spiked bat and hitting the ground near his groin.
- No-Holds-Barred Beatdown: Steve's second onscreen fight with another human also ends with his face being repeatedly punched into the floor until someone intervenes, Max in this case.
- No-Sell: Just when it seems like Steve is going to give Billy the beatdown he has been begging for all season, the latter just shrugs off every punch with a maniacal laugh.
- Nothing Exciting Ever Happens Here: We hear a news reporter saying that they spoke to a resident of Hawkins who thought they lived in a safe town where nothing ever happens.
- Official Kiss: After their Awkward Kiss in Season 1, Mike and Eleven kiss for the second time in this episode, both now more fully aware of how they feel about each other.
- Oh, Crap!: Billy's reaction when Max threatens to smash his groin with Steve's bat.
- One Dose Fits All: Averted. The same dose of the drug that caused Instant Sedation in little Will puts hulking Billy on his ass, but takes a while to knock him out.
- Parallel Conflict Sequence: The action is split into three. Joyce is trying to delink her son from the Hive Mind, the boys and Max draw the Demodogs away from the gate, and Hopper and Eleven try to Seal the Breach to the Upside Down.
- Pass the Popcorn: As the military finishes withdrawing from Hawkins Lab, Bauman is sitting in his camping chair watching them leave. And drinking beer. And smiling. And saluting. And laughing. And waving. Really, popcorn with some schadenfreude on top. For an added bonus, he doesn't live in the city or, judging by how Nancy and Jonathan had to sleep in a motel to get to his place, anywhere particularly close to it. Season 3 confirms he lives in Illinois.
- Pedal-to-the-Metal Shot: A closeup shot during the Kids Driving Cars scene shows that they had to tape a box to the accelerator because Max was too short to be able to reach it.
- Post-Victory Collapse: Eleven collapses from exhaustion after having shut the gate. Hopper is there to hold her safe in his arms.
- Power Floats: When Eleven taps into her power more fully to close the breach she starts to levitate.
- The Power of Hate: While closing the gate, Eleven is able to tap more fully into her power when she remembers Kali's advice to channel her rage over the trauma she's been subjected to at the lab.
- Pre-Asskicking One-Liner: Steve to Billy before punching him in the face.Billy: So dead, Sinclair! You're dead.Steve (tapping Billy's shoulder from behind): No. You are. — (punch)
- Psychic Nosebleed: This time, Elevan bleeds from both nostrils as she uses a lot of power in trying to close the gate.
- Replacement Goldfish: After Mews the cat died, Mrs. Henderson is seen snuggling a new kitten named Tews.
- Reusable Lighter Toss: In order to start a fire that would draw the Demodogs away from the facility, Steve tosses his Zippo lighter onto a large pool of gas they created in the tunnel.
- Rewatch Bonus: The book Karen is reading right before she meets Billy has a muscular man on the cover that looks just like him.
- Sealed Evil in a Can: The Mind Flayer still has total dominance over the Upside-Down, but Eleven closing the Gate has prevented it from entering our dimension. All it can do is seethe at the heroes at the Hawkins Middle School in the Upside-Down.
- Seal the Breach: The main characters set out to close the interdimensional rift that allowed the Mind Flayer and its minions to enter our dimension. They manage to do so with Eleven's powers.
- Stacy's Mom: When Nancy and Mike's mother Karen Wheeler answers the door in a bathrobe and is flustered to find the hunky Billy Hargrove (looking for his little sister, who hangs out with Mike) in front of her, who starts hitting on her hard.
- Tainted Veins: Dark veins appear all over Will's face as the virus is driven out of his body.
- Tears of Joy: Mike honestly sounds like he's about to cry upon being reunited with Eleven, and Eleven actually does weep a Single Tear when they hug. Joyce also breaks into tears after hugging Eleven.
- That Didn't Happen: Seems to be how Billy and Max reconciled her threatening him. He sees her mom doing her hair for the dance (at which presumably she'll be with Lucas), but though they lock eyes momentarily, he simply keeps walking.
- Throw the Dog a Bone: After Dustin gets rejected at the dance and is left without a partner, Nancy, who's chaperoning, takes pity on him and dances with him. She assures him that girls at his age are idiots and they'll be all over him in a few years.
- Time Skip: The epilogue takes us one month ahead in time.
- Unwillingly Girly Tomboy: Max dislikes being dressed up "pretty" by her mother for the school dance.
- Use Your Head: Billy headbutts Steve during their fight.
- Villain Song: "Every Breath You Take" playing in the background isn't referring to Mike and Eleven; it's referring to the Mind Flayer, who is watching them from the Upside-Down. Commentary by the cast and crew even states that the Mind Flayer's thoughts are "You belong to me", which are lyrics in the song.
- What the Hell, Hero?: Mike calls Hopper out for having hidden El for the last year. Hopper doesn't try to apologize, doesn't expect Mike to forgive him, just accepts that Mike is upset and is right to be upset. It helps him in his own growth, understanding his own issues with his daughter's death.
- Where It All Began: Eleven finally returns to Hawkins Lab, the place she escaped from in the first episode of season 1.
