Buddies Back to Back

"The only way to fight a chemical enemy is to use some chemistry of our own."

— Senku

To make antibiotics, Senku and the kingdom of science go on a quest for sulfuric acid. But the only place to find it is in a poisonous lake of acid!

Feats of Science:

Anthropomorphic Personification: Her first appearance. Ginro sees the acid pool as the seductive but deadly fairy of the lake.
Acid Pool: Deconstructed. The naturally-occurring acid lake is full of beautiful blue water, not Hollywood Acid and, while it melts birds who fall in, the real hazard is the invisible, poisonous hydrogen sulfide fumes.
Convection, Schmonvection: The Fumes, Schmumes variant is thoroughly averted.
Cowardly Lion: Ginro spends the episode overcoming his fear of the acid lake.
Defictionalized: How to Make Anything built the primitive gas masks as described in the show. Making everything air-tight is difficult with primitive technology!
Fear Is the Appropriate Response: The point of Kaseki's Rousing Speech.
"Fear is the secret to a long life."
— Kaseki
Fight Fire with Fire: See the page quote.
Hidden Depths: One of the more character-heavy episodes.
Quaking with Fear: At the acid lake, Senku seems calm and collected, but even he can't stop his hands from shaking.
More Expendable Than You: Why Chrome thinks he should go to the lake instead of Senku.
Nature Is Not Nice: Despite her beauty.
Not a Game: In the face of chemical danger, Senku gets very serious about anime-style goofiness.
This Is No Time to Panic: The gas masks can't handle the huffing and puffing of a panic attack — which is a problem when Ginro starts panicking!