After the photos from the slumber party at Rarity's have been posted on Anon-A-Miss blog, the Rainbooms go to Sunset's apartment to confront her, but when they arrived they didn't count on finding her sick in bed.
When a plague hits the city of Flankfurt, Twilight Sparkle decides to help stop the disaster. However, the longer she fights the disease, the more she thinks something else is wrong.