This article is a stub. You can help The 39 Clues Wiki by expanding it. The Serum Antidote Codex appears in Unstoppable. It shows all The Serum Antidote ingredients, and once discovered they glow green. A version of it is seen in The Unstoppable Puzzle. Antidote Codex as you first see it Antidote Codex after completion of Unstoppable Mission 1: Written in Stone The current antidote codex, as seen after adding the first two books and completing the first two missions. Complete Codex1/4Add photoS Retrieved from "https://39clues.fandom.com/wiki/Antidote_Codex?oldid=119330" Categories: Article stubs Serum Antidote Unstoppable Community content is available under CC-BY-SA unless otherwise noted.