Barb wakes up in an empty and decaying pool. She screams for Nancy and attempts to climb out but is dragged down by something unseen.
Joyce strings Christmas lights around her home to talk to Will, who can turn them on and off.
Hawkins Lab director Dr. Martin Brenner allows Hopper and his deputies to view the lab's security camera footage to prove that Will hasn't been near the lab, but Hopper realizes it is fake. He decides to take Deputy Powell with him to visit the local library to research Hawkins Lab. He finds that Brenner has been involved in several shady government projects studying the supernatural and that a woman named Terry Ives once accused Brenner of stealing her daughter. Though Deputy Powell is skeptical, Hopper insists that it is worth looking closer into.
Eleven has a flashback in which Brenner, whom she calls "Papa," has her put in solitary confinement for refusing to telekinetically harm a cat. When she in her panic uses her powers to kill the two orderlies manhandling her, Brenner is impressed.
Nancy worries about Barb, who is missing. Steve and his friends discover that Jonathan took photographs of their house party. They gang up on him and destroy the photos and his camera. Nancy, however, discovers the picture of Barb by the poolside amongst the torn photographs and returns to Steve's house to search for her.
Nancy finds Barb's car and sees the creature in the woods. Joyce establishes a code with Will using the lights, which he uses to tell her that he is alive but unsafe. He tells Joyce to run as a creature begins to climb through her wall. Will's apparent body is discovered in the water at a quarry.
This episode provides examples of:
- Animal Testing: Just to remind us that the people at Hawkins Lab are not nice, one of the experiments we see them conduct with Eleven involves trying to force her to use her psychic abilities to kill an adorable little cat. She refuses to do so. The two orderlies who try to manhandle her into a Punishment Box, however...
- Ankle Drag: Happens to poor Barb as she tries to crawl out of the pool to escape the monster.
- Awesomeness by Analysis: Chief Hopper figured out that the security tape footage is fake because it was not raining in the footage when a thunderstorm happened during the first night of searching for Will.
- Bad Boss: Dr. Brenner does not seem particularly distraught at the violent psychokinetic deaths of two of his employees.
- Brick Joke: In the previous episode, Dustin presses El to make the Millennium Falcon model fly. Her refusal is taken as a sign that she can't manage that feat. In this episode, Eleven makes the toy fly with ease while alone.
- Bullying a Dragon: The orderlies at the facility where Eleven was experimented on. They may not have known the details, but they should've known and seen enough to know that manhandling Eleven might be a bad idea.
- Caught Coming Home Late: When Nancy returns home late from the party, her mother is waiting in the corridor to berate her.
- The Charmer: Hopper has apparently cut a swathe through the single women of Hawkins including, as we learn in this episode, the local librarian. Though it's subverted in her case, since their relationship (such as it was) apparently ended with Hopper dumping her without a word, she's not pleased to see him again and when he tries to sweet-talk her into helping him read through the microfiche archives to find information on the Hawkins Lab, her response is to snort derisively and stalk off.
- Coming and Going: The episode begins with a scene of Steve and Nancy having sex for the first time being interspersed with a scene of Barb running from and eventually being killed by the Demogorgon in the Upside Down.
- Contrived Clumsiness: Steve pretends to hand Jonathan back his camera but intentionally drops and destroys it in the process.
- Downer Beginning: The episode starts with Barbara being killed.
- Downer Ending: The police pull what is thought to be Will's body out of the lake, and an enraged Mike yells at Eleven, asking why she lied to them and said that Will was alive, and then leaves when Eleven can't give any answers. He runs home and breaks down sobbing in his mother's arms.
- Her Boyfriend's Jacket: Nancy goes home in Steve's jacket which raises questions from her mother.
- The Immodest Orgasm: Steve's friends tease Nancy by emulating her supposedly loud noises during the previous night at Steve's house.
- I Need to Go Iron My Dog: Nancy comes up with a lame "have to do something with my mom" excuse to leave Steve and investigate Barb's disappearance.
- Insistent Terminology: Lucas makes it very clear that it's not a slingshot, it's a wrist rocket.
- Interplay of Sex and Violence: The demogorgon hunting Barb intercut with Steve and Nancy have sex, driven home when Steve's and Nancy's fingers intertwine only for a cut to Barb's hand desperately clinging to the pool ladder.
- It's All About Me: Steve's self-absorbed reaction to Nancy's concern about Barb echoes Nancy's own self-absorbed reaction to Mike's concern about Will in the first episode.
- Karmic Death: Eleven displays her telekinetic powers (possibly for the first time, possibly as scaling up from the Coke can) when she refuses to harm a cat and is dragged by two Mooks into a small closet-like space for punishment; instead of the cat, it's her tormentors who die when she panics at the thought of being trapped.
- Montage Out: This episode ends with Peter Gabriel's cover of David Bowie's "Heroes" playing over images of Mike and Joyce in different locations dealing with the news about Will's death.
- Neck Snap: We see Eleven killing a security guard this way, along with a Sickening "Crunch!" sound.
- Not Staying for Breakfast: Nancy sneaks back out of the house while Steve is asleep.
- Once for Yes, Twice for No: How Joyce communicates with Will before setting up the alphabet on the wall.
- Operation: [Blank]: Mike coins their mission to find Will "Operation Mirkwood".
- Pietà Plagiarism: The iconic scene of Brenner carrying Eleven in his arms away from the Punishment Box.
- She Is Not My Girlfriend:
- Mike has this reaction when Lucas accuses him of having a crush on Eleven.
- Nancy denies that Steve is her boyfriend when her mother asks about it seeing that Nancy is wearing Her Boyfriend's Jacket.
- Skilled, but Naive: Left alone in Mike's basement for the second day in a row, Eleven gets bored and spends some time exploring the house. She's a sheltered badass, still a kid curious about her new surroundings.
- Softer and Slower Cover: Peter Gabriel's rendition of David Bowie's "Heroes" at the end.
- Soundtrack Dissonance: The episode opens with Foreigner's romantic "Waiting for a Girl Like You" playing over Nancy and Steve making out while Barb in the Upside Down is being chased by the Demogorgon.
- Standard Snippet: "Holly, Jolly," the TV shows a clip of President Ronald Reagan saying, "Today, Syria has become a home for sev—". A simple search reveals that to have come from his address to the nation on Lebanon and Grenada
from October 27, 1983. Depending on the writers' attention to detail, this could be an exact date or a "close enough" bit of stock footage. - Their First Time: Nancy loses her virginity to Steve.
- Titled After the Song: Derived from the Burl Ives song "A Holly Jolly Christmas".
- Traumatic Superpower Awakening: Eleven unleashes the full potential of her Mind over Matter power when the orderlies try to put her in the dreaded Punishment Box. Dr. Brenner is impressed. It makes one wonder if he might have invoked this situation to begin with.
- Whoosh in Front of the Camera: We see the Demogorgon woosh across the foreground when Nancy looks for Barb in the woods.
- Why Don't You Marry It?: Quoted by Lucas when he gives Mike a bad time for his liking of Eleven.
