In the Castle of Friendship, Twilight is sick in bed with a spring allergy in her horn. Spike has tried every remedy he can think of, to no avail, and Applejack, Fluttershy, Rainbow Dash, and Rarity gather at Twilght's bedside to see if they can help. Unfortunately, when she sneezes, her magic goes out of control and affects them in bizarre ways. One of Rarity's front hooves grows roller-skate wheels; Fluttershy is teleported to and from someplace extremely cold, shivering and covered with ice; Applejack begins flying around the bedroom without wings; and Rainbow Dash can only speak in sound effects.
Pinkie Pie arrives with a potion brewed by Zecora that instantly cures Twilight and undoes all the wayward magic, but it has the minor side effect of turning her into a baby. The rest of the ponies hurriedly clear out, leaving Spike to take care of her on his own.
Tropes:
- Big Damn Heroes: A variation: Pinkie comes in with a cure from Zecora.
- Body Horror: Rarity's hoof grows wheels due to Twilight's magic, and yes, she does try pulling them off at one point.
- Bread, Eggs, Breaded Eggs: Spike has tried to find a cure with poultices, soup, and a poultice made from soup.
- Don't Touch It, You Idiot!: Spike tries to warn Rarity against touching the sparkly motes of magic Twilight just sneezed, but he's not quick nor firm enough and Rarity isn't paying attention, resulting in her hoof getting magicked.
- Flight: Applejack zooms uncontrollably around the room, thanks to Twilight sneezing on her.
- Fountain of Youth: Zecora's cure for Twilight has an unfortunate side-effect: it transforms her into a baby alicorn. Thankfully, it's implied to be temporary.
- Magic Antidote: Twilight believes the allergy has to run its course because she couldn't find a remedy in her books, but Zecora provides a potion. It cures her immediately, but unfortunately there's a side-effect...
- No Ontological Inertia: Once Twilight drinks Zecora's cure, every one of her friends (minus Spike and Pinkie Pie, who had avoided being blasted) revert back to normal.
- Screw This, I'm Outta Here: The rest of the ponies' reactions to Twilight turning into a foal. Spike's the one to have to take care of her.
- Sick Episode: The whole short is about Twilight suffering from a horn allergy, and her friends having to deal with the consequences.
- Sneeze of Doom: Twilight's allergy causes her to sneeze out bursts of magic that have strange effects on whoever gets hit.
- Taking the Bullet: Applejack pushes Rarity out of the way of Twilight sneezing.
- Wacky Sound Effect: Rainbow Dash can only speak in sound effects after she gets blasted: a jackhammer, a cuckoo clock, a squawking chicken, a yowling cat, and The Six Million Dollar Man's iconic "bionic sound".
- Wild Magic: Twilight's sneezes are causing uncontrollable bursts of magic that have random effects on whoever is hit, including Rarity's hoof growing wheels, Fluttershy being teleported and coming back freezing, Applejack randomly flying around and Rainbow Dash making wacky sounds instead of speech.
