- Story by Ted Anderson, Art by Agnes Garbowska
A strange ailment strikes every pony in Ponyville, and Spike, immune to whatever it is, rushes out to Zecora in the Everfree Forest to get her help. Zecora collects a number of potions and tools to help out, as well as a bird named Avery, trained by Fluttershy, that can help to intercept any coughs directed her way.
In town, Zecora goes to work to try to understand the illness. She sees that it has traveled as far as Sweet Apple Acres, and tries to understand how it could travel so far, so fast. After they see the Apples, Spike recognizes he is a different species from the ponies, which likely has made him immune to whatever it is; but this also leads to both realizing how far they are from others of their kind and feel a bit of homesickness.
They stop at Fluttershy's cottage, but she has been so sick that she's been unable to feed her animals properly, and just has laid out stashes of food for them. Avery is distracted by a pile of birdseed that when Fluttershy sneezes on Zecora, he is not there to block it. Fearing Zecora is now infected, they race off to isolate Zecora, but surprisingly, she does not come down with anything, and now they suspect that zebras are also immune. With this, the two set to work to try to find anything pony-related that might have caught it, but still cannot find a solution.
The two take a break to have a meal, and discuss the results. Shortly, Zecora suddenly feels ill and has caught whatever the ponies have had. Spike deduces that it is not an infection but something on the hay that Zecora and the rest of the town would have eaten, while he had his normal gem diet. Quickly discovering the fungus that has covered the town's hay supply, Spike begins to prepare a broth to help cure Zecora. By the time the Canterlot Disease Corps have arrived, everypony is cured. Spike goes off to thank Zecora for her help, and he offers to visit her more and invites her to visit him in town.
This issue provides examples of:
- Artistic License – Biology: Apparently in Equestria, diseases always show symptoms within sixty seconds, because this is how Spike deduces that the disease isn't transmitted through sneezes.
- Call-Back: Spike brings back up events from the episode "Dragon Quest" and from Luna/Spike Friends Forever (with Mina the dragon), while considering himself an outsider to the normal pony folk of Ponyville.
- Chekhov's Gun: Early in the story Spike and Zecora are out doing house calls while at the Cakes' home the twins are shown to not be infected, with the fact that the twins have yet to begin eating solid food (such as the infected hay) being mentioned in passing.
- Furry Reminder: The ponies and Zecora get sick from eating infected hay.
- Labcoat of Science and Medicine: Spike and Zecora don a set when they begin researching the infection in earnest.
- Last of His Kind: While Zecora and Spike aren't the only zebra and dragon in Equestria, they sometimes resent being the only ones of their species living among ponies.
- Non Sequitur: While infected ponies still talk normal, Zecora, for whatever reasons, speaks in nonsense when she's infected.Zecora: "It appears I'm feeling a bit purple. As if there's something in my rythym."
- Obviously Not Fine: Spike tells Zecora that she is infected with the apparent disease that's been going around, and she replies that she's "healthy as a wolf", even though she has gotten spots and hypno-eyes.
- Polka-Dot Disease: Red spots are one of the disease's symptoms.
- Rhymes on a Dime: Spike makes a couple attempts to copy Zecora's rhyming. Also subverted, as getting sick makes her start speaking in blank verse instead.
- Shout-Out:
- The Canterlot Disease Corps is a play on the Center for Disease Control.
- Spike reads from a book called "Spores, Molds, and Fungus"
- Sick Episode: Exaggerated. Everypony in Ponyville gets sick, except Spike.
