In the 1940s, the world was in turmoil, and it was crucial to decipher the enemy's communication codes in a timely and accurate manner. Rong Jinzhen has shown amazing mathematical talent since her childhood, and because she solved the problems assigned by her math teacher, she was noticed by more people, and even walked into the door of code-breaking by mistake.

Frederick Fitzell is living his best life—until he starts having horrific visions of Cindy, a girl who vanished in high school. After reaching out to old friends with whom he used to take a mystery drug called Mercury, Fredrick realizes the only way to stop the visions lies deep within his own memories, so he embarks on a terrifying mental odyssey to learn the truth.

A documentary about conspiracy theories takes a horrific turn after the filmmakers uncover an ancient and dangerous secret society.