In a flashback, Eleven awakens in the Upside Down middle school, having just destroyed the monster at the end of the first season. After escaping the Upside Down, she goes to Mike's house but find it swarming with government agents looking for her. To avoid them, she hides in the woods.
In the present, Eleven asks to go trick-or-treating. Hopper says it's too risky, but promises her to be home early with candy so they can celebrate Halloween together. However, while working, he learns the strange blight has spread to farms all over town, and spends all day investigating it, and eventually has to break his promise.
Dustin and Lucas tries to recruit Max for the party, inviting her to hang out with them on Halloween. While a bit skeptical of them, she doesn't outright reject the idea.
Nancy wants to tell Barb's parents about her death, but Steve insists it's too dangerous. At a Halloween party that evening, Nancy gets drunk and tells Steve she doesn't love him. Angered, Steve leaves, and asks Jonathan to take her home.
The party go trick-or-treating dressed as Ghostbusters, and are joined by Max. While Lucas and Dustin are excited to have her with them, Mike is greatly annoyed by her presence. But the quest for candy is suddenly cut short when Will has another vision of the shadowy monster from the Upside Down trying to catch him. Mike brings the shaken Will home to discuss his visions, during which he admits to him that he is still trying to contact Eleven.
Frustrated with Hopper breaking his promise, Eleven tries to contact Mike but fails. When returning home, Dustin finds that the noises from his trash can was caused by a strange creature hiding in it.
This episode provides examples of:
- 1-Dimensional Thinking: Downplayed. When Billy is about to run over Dustin, Mike, and Lucas on their bikes, they don't think about getting off the street until the last possible moment.
- Alien Kudzu: Averted, then played straight. The rot killing the pumpkins has spread to other crops, making it seem like a plant blight. However, Hopper then discovers the surrounding trees covered by a fungus/slime combination which he's only seen in the Upside Down.
- Beautiful Dreamer: After tucking Nancy into bed, Jonathan briefly pauses while closing her door to admire her sleeping form.
- Bedsheet Ghost: Eleven dons a sheet in this fashion hoping to convince Hopper to let her go Trick-or-Treating. It even gets him to jump when he first sees her.
- Brick Joke: In the previous episode, Bob mentions that he loves Kenny Rogers, unaware that Jonathan was using him as an example of extremely boring people. In this episode, he dances with Joyce to a record of "Island In The Stream."
- Calling Me a Logarithm: Inverted. Dustin thinks being called "presumptuous" is a good thing.
- Crazy-Prepared: Hopper has developed a security system with Eleven to keep her safe, from booby-traps outside the cabin, to coded knocks at the door. He also won't let Eleven go trick-or-treating, and has become extremely protective of her in general. However, considering she is being hunted by the government, who are still closely watching Hawkins, this is entirely justified.
- Curse Cut Short: How the episode ends. Dustin finally confronts the thing inside his trashcan once it starts rattling violently, throwing open the lid and looking inside. His reaction?Dustin: Holy sh—
(cue Ghostbusters theme and end credits)
- Does This Remind You of Anything?: Eleven plopping out of the hole in the wall and into this world is reminiscent of a baby plopping out of the womb at birth.
- Drives Like Crazy: Billy nearly runs the boys down simply to screw with Max, who he for some reason blames for their being in Hawkins.
- Drowning My Sorrows: Nancy attempts to binge drink at the Halloween party to forget about her troubles, following Steve's advice to act like stupid teenagers attending a stupid party for the night. However it only makes her emotionally volatile, to the point that she lashes out at Steve when he realizes how drunk she is and tries to take her home.
- Expository Hairstyle Change: Eleven's backstory of how she survived in the woods is shown in flashbacks. Her hair growing longer and shaggy clues us in about the time skips between events.
- Friendship Moment: Two:
- Will shares what he is seeing with Mike, who tells Will about feeling that he sometimes thinks Eleven is around. The two agree that, if they are going crazy, at least they are going crazy together.
- Jonathan takes a near blackout drunk Nancy home, and gently tucks her into bed.
- Halloween Episode: This episode takes place on Halloween, complete with much of the cast donning costumes and going Trick-or-Treating, or attending a Wild Teen Party.
- Implicit Prison: The cabin Hopper hides Eleven in has become a prison for her over the months.
- Internal Reveal: How did Eleven escape the Upside Down? She walked over to a previous tear in reality made by the Demogorgon and passed through it herself, just minutes after killing the monster.
- In Vino Veritas: Nancy gets drunk at the teen party and starts laying into Steve about covering up Barbara's death from the previous year. Having assumed she's saying how she truly feels, Steve is hurt and leaves her at the party.
- Jump Scare: A few.
- The episode opens with a loud and sudden flashback to Eleven defeating the Demogorgon.
- When Eleven pops up behind Hopper in her ghost costume.
- When Max jumps in front of the boys wearing her Halloween mask.
- When a group of three older boys jump out in front of Will.
- Keeping Secrets Sucks: Nancy hates that she's not allowed to tell Barbara's parents about what happened to their daughter and lashes out on Steve about it while drunk.Nancy: No, you. You're...bullshit.
Nancy: You're—you're pretending like—like everything is okay. You know, like we didn't—like we didn't kill Barb? Like, like, "it's great. Like, we're in love and we're partying. Yeah, let's party, huh? Party. We're partying." This-'tis bullshit.
- Literal-Minded: Eleven doesn't understand when Hopper reacts to her costume and assumes he just incorrectly identified who she was dressed as.Hopper: Jesus!
Hopper: Yeah I see that.
- Living Shadow: Whatever the Eldritch Abomination in the Upside Down truly is, its limbs seem to end in mist-like shadows. It adds substantially to the creep factor.
- Mundane Utility: Eleven using her telekinesis to turn the knob on the TV.
- Nightmare Fuel Coloring Book: Will starts creating creepy drawings, much to his mother's concern.
- Not So Above It All: Jonathan shows off a more humourousu and silly side of himself when he repeats Bob's Dracula impression of "I hope it doesn't suck!" when dropping Will off with his friends.
- The Oner: A single continuous shot tracks Billy, then Nancy, then (briefly) Steve across the Halloween party they're attending.
- The Promise: Hopper makes a big promise to Eleven to be back at 5:15 pm, but he gets distracted by an investigation and turns up late. He seems genuinely regretful, but Eleven is obviously angry and won't talk to him.
- Scare Chord: A scare chord plays early on when Eleven sneaks up on Hopper dressed as a ghost. It's Played for Laughs.
- Screams Like a Little Girl: Lucas lets out a high pitched scream when Max jumps them, which she makes jabs at.
- Screw This, I'm Outta Here!: Steve's immediate reaction when Nancy belittles him and implies that she doesn't love him is to leave the party out of anger and disappointment.
- Serious Business: The boys treat the fact that they were the only ones to arrive at school in costume for Halloween with the same kind of gravitas they would when dealing with the Upside Down.
- So Unfunny, It's Funny: Bob's brand of humor is funny mostly because it's not actually funny, especially his vampire puns.
- Taught by Television: When Eleven is holed up in the cabin in the woods waiting for Hopper to come back after having crossed over from Upside Down, she watches TV shows and old movies on TV, parroting the dialog in an effort to both learn about society and better speak English.
- That Came Out Wrong: While chatting with Samantha at the party, Jonathan suddenly asks, "Kiss?" He quickly clarifies that he is trying to identify her costume.
- Time-Compression Montage: Throughout the episode, a few quick montages show what happened to Eleven after the end of Season 1. First she's seen surviving destroying the Demogorgon right after it happened, then there are two separate scenes of her living in the woods around Hawkins several months later, complete with her hair growing out.
- Title Drop: The title of the episode is said by a couple of bullies wearing masks when they encounter Will while he's picking up candy and mock him.
- Trunk Shot: When Dustin looks into the trash bin to find the little creature, the camera is from the inside of the bin's point of view.
- Vomit Indiscretion Shot: A partygoer rushes out of the house and spews his "pure fuel" just as Jonathan arrives.
- Wham Line: Played for Laughs. The younger boys are shocked when they arrive at school on Halloween and see that they're the only ones who dressed up. "Why is no one else wearing costumes?"
- What Does She See in Him?: While Jonathan doesn't think Bob is a bad person, he's baffled by why his mother is attracted to him since he's an absolute dork. While indeed dorky, Bob is otherwise shown to be nothing but loving and kind to Joyce and her children, and Will appreciates how Bob is apparently the only person in Hawkins to treat him normally.
- Wild Teen Party: Billy, Nancy, Steve and Jonathan all attend a Halloween party being hosted by a classmate of theirs. It's full of teenagers dancing, drinking and letting loose, naturally.