One of the most chilling aviation mysteries in modern day: a Boeing 777, carrying 239 people, vanishes over the Indian Ocean; nearly a decade later, no one knows what really happened to Malaysia Flight 370.

It might be the world's most mysterious book: a medieval manuscript filled with unidentifiable drawings, written in a secret language so complex that even the world's best code breakers can't crack it. It's obsessed everyone from scholars to conspiracy theorists. What is the Voynich Manuscript? And who wrote it?