Page 753 — Dilution Solution
The funny thing about doing the Story Time 3 project is that it forced me to get up to date on the show. Even though I knew the comic was going to go in this direction, I didn't actually have the episode on-hand until I updated my library so I could go screencap-hunting for Story Time.
Transcript:Rainbow Dash: And whaddaya know, my History sucks.
DM: No magical Nat 20 this time?
Rainbow Dash: Nope.
Fluttershy: Um, I was thinking… Since this has to do with a common, natural disease… Can I roll Nature for knowledge?
DM: Hmm… Sure, go for it.
Fluttershy: <roll> 31.
DM: Nice! That… <shuffle> is sufficient. The feather flu can't be cured, per se, but you've heard of a legend that might provide an alternate solution. There's a potent elixir you can make that can keep ponies at the peak of health, at least temporarily.
Twilight Sparkle: So if they take this potion, our pegasi can basically ignore the flu?
DM: For a while, yes.
Twilight Sparkle: How do we get it?
DM: It requires a very special and very rare ingredient. The magical pollen of a Breezie.