A 240-page book covers its pages in looping, unreadable script and illustrations of plants that match no known species, alongside diagrams of nude women bathing in green liquid and charts that look astronomical but follow no known system. Named for Wilfrid Voynich, the New York rare book dealer who brought it to public attention in 1912 and tried, and failed, to sell it to wealthy collectors, the manuscript sat unclaimed until it entered Yale's Beinecke Rare Book and Manuscript Library after his death. The film follows the long list of people who have tried to break it: the same American codebreakers who cracked Japan's Purple cipher in World War Two, historians chasing named suspects as author, and physicists running the vellum and ink through modern lab equipment. Some of those historians argue the whole thing is an elaborate hoax, possibly Voynich's own fabrication built to look ancient and valuable. The film pushes past that debate into a newer approach, testing the physical material itself for what it can reveal about the manuscript's true age and origin.