During a sleepover, Lena's wayward magic causes her, Webby, the triplets and Violet to enter each other's dreams, where the image of Magica de Spell is stalking her.
Cut to 4:01 AM. The kids are all exhausted, having eaten sugar, done pillow fights, played games, the works. All the others want to just sleep, but Lena for suspicious reasons wants to keep going, despite her amulet inside her body now causing minor magic flareups. So, she runs to the bathroom to splash water in her face, only to suddenly see Magica's eyes and a lock of black hair in her face. She shakes it off, but by the time she gets back, the boys and Violet have all turned in for the night. Giving a reassuring smile, Webby assures Lena that she has glow in the dark stars, so she doesn't have to be afraid of the dark, and eventually, Lena succumbs to exhaustion. Of course, as she finally nods off, a small pulse of magic comes from her head.
Waking up on a beach together, the kids are really confused by their situation. While this scenario is something Webby always dreamed of, when she harvests a coconut, it has a hamburger inside. Then when Louie tries to call for help on his phone, all he can see is pictures rather than numbers, and a second later, he's holding a banana instead. And when Webby gets a new look to appear like Scrooge, and a unicorn shows up to give them a quest, Violet finally figures it out. While Lena is in denial about their situation at first, Violet deduces that they're clearly in a shared lucid dream brought on by Lena's magic. Which she demonstrates by instantly growing a flower in her hand which then walks off. When probing a bit deeper, Lena eventually admits she's been having trouble sleeping, and wants to wake up to get them out of this situation, but as Huey points out, waking sleepwalkers is bad enough for the sleeper. What happens if you unnaturally wake a sleepdreamer with magic? So, the whole group take to the sky to fly! "Because we can!" Well, at least the others do. When Lena tries, she grows batwings instead, and decides to walk after them instead.
Eventually linking up down the road, they next spot a school in the distance. But this isn't Webby's dream school: it's Dewey's! So, they enter Dewey High, where Dewey sings because that's what you do in high school, water fountains put out basketballs, the cast of Dewey Dew-Night praises him. He does have a Love Interest floating around, but he's uninterested in that for now, so it's only a blob at the moment. He has rival jocks, a giant poster of himself, a mysterious image of him crying on a moon made of his tears, and of course, a mascot. Briefly separating from the group, Lena sees the mascot glitch around, before an image of Magica pops up in the hall.
Terrified of Magica coming towards her, Lena pulls the fire alarm, dropping grape-flavored Pep on the image, melting it. But it also annoys Dewey for missing a dance number. Still, the rest of the kids agree it's time to move on to a new dream, so with Violet suggesting they can focus to choose the next dream, Louie takes point. Leading them back into the mansion tv room, Louie appears to them as a green fat cat.
This is his dream to be perpetually pampered and lazy, to which the plays with pep cans, gets petted by the others, and even takes a nap...IN the dream! But Lena is running behind, and when she comes through, she's a wolf. Something Violet identifies as a possible case of a violent tendency, or Outsider Syndrome. Then a dream Beakley says she "needs to call animal control", which turns out to be another image of Magica. This pushes Lena to get the others to another spot, which looks just like the room the triplets sleep in.
Then they notice that Huey is 3 bunkbeds tall with extremely long legs. His vision of himself as a "tall, distinguished, mature oldest sibling." Dewey for his part is disturbed by this, saying that ideal doesn't match what Huey's done, but he shoots back he's "not good at imagination stuff". Trying to give the others pickles, Huey opens the jar with his legs, but accidentally drops it, then tries to extend his arms to pick it up, only to create crazy noodle arms which disturbs everyone. Having enough, Dewey prompts them to try out new dreams away from all this through a dream montage.
So, the kids bounce on Jello towers, ride ottomans and rocket ships, walk through candy rain. Create "Phoey" the lost brother, run through the fields alongside a launchpad whale. And all along the way, Lena keeps seeing Magica everywhere.
Finally, they land in a recreation of the Duckburg library, which is Violet's Humble Goal: she just wants to read more as a dream. But still Magica continues to haunt Lena secretly, scaring her greatly. Then everyone seems to hear Scrooge knocking on the door of the real world, telling them to get up since it's 6 AM. Lena wants this, but her magic and exhaustion still won't get her up, and worse, she starts to truly turn green. Which Lena tries to hide from the others despite their questioning, only for Magica's image to gesture her to come, sending her plumitting into her own sweater. The other kids leap after her, only to arrive at the doorstep of a dark castle. Webby asks if this is Lena's ideal dream, but Huey rightly points out, "I think this is more nightmare."
Awakening in the middle of the castle, Lena is now fully green, and Magica is now full in front of her, trying to use gaslighting to convince Lena to come back to her. As she goes though, they begin to hear the others coming up to save her, picking up Lena's spirit that her friends will save her. Won't see her as a monster or anything like Magica. But then somehow, Magica turns Lena into a mirror image of her powered self and hides in the staff by the windows. And right at that moment, Huey uses his large legs to open the door and enter the room with each child in their ideal dream self.
Webby, on seeing "Magica" demands to know where Lena is, and despite Lena trying to say she's not Magica, her tone doesn't convince them, along with Webby's proclamation of calling her a monster turns Lena into a winged, fire breathing version of Magica. Uncontrollably causing mayhem, and leading to the children attacking her with Basketballs, throwing Louie at her in cat form, or hitting her with magical blasts from a book Violet was carrying. Huey also accidentally drops a chandelier on Webby, which Lena pushes her away from despite the attacks.
After getting smacked around, Magica uses a mirror to tell Lena to just give in since all this being good was just leading to hurt. And Lena seems on the verge of giving up. Then Webby notices the friendship bracelet on Lena's arm, and stops her, apologizing for not seeing that it's her. She asks if this is what's been bothering her, and Lena can no longer hide it. Opening up on how tiring it is to have the Despell legacy over her head and thinking she is still nothing but Magica. However, Webby rightly points out that even when they were against her, Lena still chose to protect the others from her messes. Saying that "You worry so much about being good, but you're good enough."
Lena starts to get up, but then the Magica of her dreams grabs her, and tries to pull her into the mirror with her. Shocked, all the kids form a magical chain, loaded with blue friendship magic, pulling and trying to protect their friend. However, Magica has a better grip, and slowly begins pulling Lena's hand away. Distraught, Webby sheds a tear that hits Lena's beak. But doing so causes Lena's internal magic to flare up, sealing Magica away, and awakening all of them at last. Though Huey for his part is disappointed not to have long legs again.
Just then, they notice a drone outside, and going to the edge of the backyard, they see the physical Magica Despell lurking in the woods, still using words to try and convince Lena to come back. But then she comes into the light, and they see not a regal magician, but a disheveled, dirty hobo wearing a brain prober device. Finally seeing Magica for the broken, pathetic duck without any merit, Lena uses her internal magic to break the device, Not Afraid of You Anymore at last. So, with no more concerns, the children all return to the mansion, happy and even possibly considering a nap later, even with Magica futilely screaming threats at them as they go.
- Absentee Actor: Scrooge only makes a brief voice cameo while Donald and Launchpad don't appear at all (unless one counts the walrus version of Launchpad in the dream).
- All There in the Script: Some dialogue cut for time explained that Lena has been living with Violet, which is how Violet knew Lena hasn't been sleeping.
- Amazing Technicolor Wildlife: Louie dreams that he's a green cat.
- Ambiguous Gender: Dewey's dream high school love interest's voice is a blend of masculine and feminine voices, which fits with him not really being ready to think about romance.
- An Aesop: If you're having a problem, you shouldn't be afraid to tell your friends. They'll want to help you rather than have their feelings protected.
- Animorphism: In Louie's dream, he's a fat lazy cat living in Scrooge's mansion. In the same dream, Lena turns into a wolf.
- Anxiety Dreams: Lena is worried that she'll turn into Magica, which manifests itself throughout the dreams.
- Artistic License Biology: The coconuts Webby knock out of a tree are drawn resembling the endocarp of a coconut, lacking the smooth and green husks that cover coconuts while they are still on the palm. Justified in that they are not real coconuts.
- Badass Decay: In-Universe. Seeing Magica reduced to using stolen tech (which Lena easily destroys) in a desperate attempt to take Lena's magic for herself causes the kids to lose any fear of her they still had.
- Baleful Polymorph: Lena is gradually transforming into Magica during the dream, revealing her fear of becoming just like her. She also transforms into a wolf in Louie's dream. She fully transforms into Magica just as the others come to rescue her, and attack her thinking she's the real Magica.
- The B Grade: Huey demands they leave Dewey's dream after he gets an F- in "Dewology" class. Especially as Dewey got an A-plus-infinity.
- Big Man on Campus: Dewey's dream is about being one of these in an idealized high school (he, his brothers and Webby are homeschooled and have never actually gone to one).
- Big "WHY?!": Dewey's reaction to Tall Huey is to let out a string of horrified cries of "Why?!". When Huey makes himself grow extra-long arms to go with his legs, a horrified Webby shouts "Oh, why?"
- Body Horror: Dewey is grossed out by Huey's dream of having long legs, more so when his arms grow to match.
- Brick Joke: After "Whatever Happened to Donald Duck?", the kids dream up Phooey, a fourth triplet whose signature color is mustard yellow.
- The Bus Came Back: Magica reappears for the first time since "The Shadow War".
- Cats Are Lazy: Louie's dream is to be a cat specifically to live out this trope.
- Chekhov's Boomerang: Friendship bracelets again, though this time they're proof of identity instead of magical talismans.
- Color-Coded for Your Convenience: The dreamscapes. Pink for Webby, red for Huey, blue for Dewey, green for Louie, violet for Violet, and dark purple for Lena's nightmare.
- Creative Sterility: When Dewey points out how lame Huey's dream of having comically long legs that make him taller than his brothers is, Huey admits he's not very good at using his imagination.
- Dartboard of Hate: The triplets are shooting dart bullets at a photo of Magica de Spell. A stray bullet accidentally hits Lena's photo.
- The Dog Bites Back: After being abused by Magica for literally her entire life, and now that Magica's been reduced to begging Lena to give her powers back, the answer is no. The episode ends with the crew laughing at her and commenting "I don't need you. You need me!"
- Dream Episode: The episode largely takes place in the shared dream.
- Dream Sue: Dewey dreams of being the best student in high school, to the point that the high school itself is based around him. Huey tries, but all he can come up with is comically long legs.
- Dream Tells You to Wake Up: Scrooge's knocking on the door makes its way into the dream, along with him yelling that it's time to get up. However, they are too fast asleep and Scrooge leaves shortly thereafter.
- Dream Walker: Because of Magica's helmet, all six kids are able to enter each other's dreams.
- Dream Weaver: After Violet points out that they are in a dream, the kids have pretty good control over the dream realm.
- Dream Within a Dream: Huey is exasperated that Louie falls asleep while dreaming.
- Egopolis: Dewey's dream is set in Dewey High, a high school all about him based off pop culture media of musical high schools he saw.
- Entertainingly Wrong: Webby sees Lena hesitant to go to sleep, determined to stay awake, and assumes it's because she's afraid of the dark. Webby says she was too and points out glowy stars on the ceiling to help. It's not until they're in the dream that Lena confesses she's been having nightmares for the past week.
- Epic Fail: Scrooge had spent who knows how many months and how much money looking for Magica after "The Shadow War". This episode reveals that not only had she been in the woods of Duckburg the whole time, on a few occasions she had been right outside McDuck Manor.
- While she's staring in the bathroom mirror, Lena's eyes suddenly change into Magica's, and some of her hair turns jet-black. Later on, she gets transformed into Magica.
- Lena is frustrated early in the story because her voice sounds so naturally sarcastic people have time taking her seriously. Later, when she desperately needs Webby to believe something incredibly unlikely, she still can't turn off the sarcasm and Webby doesn't believe her.
- Freeze-Frame Bonus: A quick glance at Louie's wings show that he has dollar sign patterns on them.
- Gaslighting: Magica has been trying to convince Lena that her friends will never accept her and that she should join her again. She even makes Lena look like herself so she gets attacked by the other kids.
- Girl of My Dreams: Averted. Dewey mentions he has a love interest in his high school fantasy, but since he's not emotionally ready for that, it only manifests as an amorphous blob.
- A Glitch in the Matrix: When the kids are in Webby's dream, Louie tries to call Scrooge, but his phone has nothing but McDuck-based emojis and makes funny sound effects. Later, Mrs. Beakley in Louie's dream speaks backward.
- Good-Times Montage: Lampshaded by Dewey wanting to do a dream montage. The montage is fun for everyone but Lena, who is still being haunted by visions of Magica.
- Good Wings, Evil Wings: When the kids dream of flying, they grow butterfly wings. Lena, however, grows bat wings and is afraid the others will find out, so she walks instead.
- Height Angst: Huey's dream is about being taller than his brothers since he feels he should be respected more as the eldest triplet.
- Hourglass Plot: Magica and Lena's situations have completely reversed; now Magica is the one who's powerless and homeless. This doesn't stop her from continuing to terrorize Lena, acting like she still has the upper hand.
- How the Mighty Have Fallen: Magica is reduced to a wretched mess hiding out in the woods desperately trying to manipulate Lena into giving her back her magical power with stolen technology.
- Hypocritical Humor: Dewey calls a clique of Beagle Boys full of themselves as he's showing everyone a high school centered entirely around him just before showing off a giant poster of himself.
- Identical Twin ID Tag: As with their usual outfits, this episode shows each triplet in signature pajamas: Huey wears a loose red nightshirt and nightcap, Dewey a blue footed onesie, and Louie a green button-up pajama shirt.
- Laser-Guided Karma: Magica bossed and abused a homeless teenager for several years, with her victim having no way to escape; now, Magica is homeless and powerless, and the teenager, the only one who can restore her magical power, is no longer under her control and is in a much better living situation.
- Lazy Bum: Louie's dream is to be a cat getting to sit around all day and be pampered, even managing to take naps while already dreaming. In the end, after they had just all woken up, he still feels like a nap.
- Lotus-Eater Machine: Played with. Magica uses a stolen prototype helmet that boosts psychic energy in order to keep Lena asleep long enough to steal back her magic.
- Low Clearance: Tall Huey keeps bumping his head on ceiling lamps.
- The Man in the Mirror Talks Back: Magica manifests herself as Lena's reflection to further drive her apart from her friends. When Lena still refuses, she tries dragging her into the mirror.
- Morphic Resonance: Webby realizes Magica is actually Lena when she sees the friendship bracelet on her wrist and saves her from the falling chandelier.
- Mundane Wish: Violet's dream is simply more time to read in the library.
- Mythology Gag:
- Once again, the "fourth" triplet, Phooey Duck, is referenced. This time, he appears in the group's shared dream, wearing yellow.
- The Killmotor Hill from the title is the location of Scrooge's Money Bin in the comics. Since the Bin is no longer on a hill in the series, it now means the hill on which his mansion is built.
- The helmet Magica uses to enter and manipulate Lena's dreams comes from a Don Rosa comic in which the Beagle Boys try to do the same thing to Scrooge. In that comic, Donald goes in after them, resulting in him sharing many of Scrooge's dreams (all of which are just Scrooge's memories from The Life and Times of Scrooge McDuck).
- Never Wake Up a Sleepwalker: Lena wants to wake up as soon as she learns she created a shared dream but Huey and Violet surmise that if waking a sleepwalker is risky, waking a dreamwalker is even riskier, so they convince her to wait to wake up naturally.
- "No. Just... No" Reaction: Dewey's reaction to long-legged Huey. It just gets worse when Huey stretches his arms as well.
- Not Afraid of You Anymore: Once she sees how far Magica has fallen and realizes that she doesn't need Magica, Magica needs her, Lena destroys her helmet and tells her to stay out of her dreams, then shows no reaction when Magica charges at the gate trying futilely to attack her.
- OOC Is Serious Business:
- Lena tries to be overly cheerful and friendly at the sleepover, out of her fear of becoming evil like Magica. Webby keeps reminding her that she's already a good person and doesn't need to overdo it.
- Magica using stolen technology instead of magic, something that Louie lampshades, confirms her Badass Decay.
- Our Werewolves Are Different: While she's not a werewolf in reality, Lena's transformation into a wolf in Louie's dream would technically qualify as lycanthropy.
- Power Incontinence: Lena has all of Magica's powers and they flare up with her emotions. She makes an extinguished candle on a cake spark into a pillar of fire and pops a balloon from emotional outbursts. Her anxiety over her nightmares, identity, and her friendships end up creating a shared dream when she goes to sleep. The ending implies that this was largely Magica's doing, though, with the aid of a helmet that somehow allows her to manipulate their dreams.
- Ptero Soarer: Magica!Lena's monstrous form shares some traits with pterosaurs, namely the small wing claws (albeit only two instead of the usual three) and going down on a quadrupedal gait.
- Puff of Logic: The unicorn in Webby's dream disappears as soon as he realizes there's no one left to dream about him. Notably, he doesn't have any visual effects or sounds accompanying his disappearance. Instead, he just ceases to exist mid-sentence. As morbid as it is utterly hilarious.
- Real After All: While Lena's fears and insecurities certainly helped, Magica really has been trying to re-possess her ex-shadow from inside her dreams.
- Recurring Dreams: Dewey mentions that in all his dreams, there is also a visage of him, cradled in a crescent moon made of his own tears.
- Retreaux: Dewey's high school dream has a strong 80s vibe to the setting.
- Rubber Hose Limbs: Huey's arms become long and extremely flexible in his dream.
- Sanity Slippage: Hiding out in the woods while trying to take Lena's magic has made the already loony Magica so much worse.
- Sdrawkcab Speech: In a likely Shout-Out to Twin Peaks, Dream!Beakley's line "A wolf in the house! I'll get animal control!" appears to have been recorded by Toks Olagundoye speaking the line backwards, then having that played backward so it sounds forwards.
- Shared Dream: Lena's magic accidentally connect all the kids dreams together during a sleepover. They mostly use the experience to have fun, but it also gives them a chance to help Lena deal with recurring nightmares she's been having.
- The title calls back to what else but A Nightmare on Elm Street. Lena's attempts to stay awake all night so she can't dream call the films to mind, as well as Magica stalking Lena through the dreams like Freddy Kruger.
- Dewey's dream of being in a high school setting where he performs musical numbers is a reference to films like Grease and High School Musical.
- Lena pulls the fire alarm, and Magica melts in the sprinklers.
- Louie as a lazy cat resembles Garfield, but green.
- Lena's wolf form bears a strong resemblance to the titular wolf from the Peter and the Wolf segment in Make Mine Music!.
- Launchpad coming out of a sea of clouds as a whale references Shenron the first opening of Dragon Ball Z
- Lena looks like one of the Gargoyles near the end, complete with a protective spirit inside her scary appearance.
- Sleeps with Both Eyes Open: When Louie says that Beakley fell asleep, it cuts to Beakley lying against the wall by the door, gasping with both eyes open. Webby says that's how she sleeps, saying "It's a spy thing".
- Standard Snippet: Lena's friend-iversary song is set to the William Tell Overture.
- Stepford Smiler: Overcompensating for her self-perception of inherently being a freaky loner, Lena styles herself as a grotesque caricature of friendliness, who bakes a cake to celebrate their one year "friend-iversary" and sings a corny song about it to the tune of William Tell Overture. Webby unironically loves it, but everyone else can tell that something's up.
- The Stoic: Violet lampshades that she affects a monotone voice, in order to avoid confusion, while they're all discussing how Lena chronically sounds sarcastic.
- Swiss Army Tears: Webby's tears saved Lena from being pulled to Magica.
- Unicorn: One shows up in Webby's dream, sending her on an epic quest.
- Villainous Breakdown: After Lena destroys the dream-entering helmet on her head and invokes Not Afraid of You Anymore, the already unstable Magica is reduced to ranting desperately. She begins to shout disturbingly violent threats while clawing through the bars of the gate like a caged animal, while the decidedly un-impressed kids calmly walk back to the mansion.
- Whole Plot Reference: The episode is one to A Nightmare on Elm Street, right down to the title.