I-- uh, I totally forgot! [ But oh yay, she is flying he back to the colosseum! With all the danger! Great! ] But it should be right where you picked me up-- it's a box that says carbon dioxide.

If I don't exchange it in the lungs, it'll disassociate become an acid! [ CO₂ + H₂0 = H₂CO₃. We're learning about the body, ladies and gents! Except one, it dissociates in the bloodstream which they are not currently in. And two, she's just panicking. ]