Keratin-Eliminating Mammal-Oriented Single-cell with Antibody-Burning Excretions. KEMOSABE disease, known more commonly as the gruesome "Meltmane Fever." A truly devastating plague with disturbing effects and no guaranteed cure known to science or magic, both modern and long past. Except one.
~~Book I~~
An outbreak of KEMOSABE across all of Equestria puts Rarity and Spike the dragon in the roles of Ponyville's last hope. With only an old pony's tale and the wisdom of Zecora to guide their way, the unlikely adventurers set course for the Purest Spring, a mythical fountain with waters said to cure any illness. Their journey is fraught with peril as they head towards Zebreria, a dark land of endless winters and monstrous creatures.
Shortly after their journey commences, Ponyville succumbs completely to the KEMOSABE, leaving only five equines- Fluttershy, Twilight Sparkle, Time Turner, and Lyra Heartstrings, and Zecora- in any shape to help. These five must work together to keep their town's withering population alive and stable with a rapidly diminshing supply of bacterial suppressants and no chance of outside help.
[For the record, the excessive capitalization in the chapter titles is entirely deliberate.]