|Powers||Spell book decoder|
|Location/Owners||Men of Letters Bunker|
|Episodes|| 10.19 The Werther Project|
10.21 Dark Dynasty
10.22 The Prisoner
10.23 Brother's Keeper
11.03 The Bad Seed
11.09 O Brother Where Art Thou?
The language Nadya used in the codex is damn near indecipherable. She was a gifted witch but a selfish pig. Once she cracked a code, she then coded its secrets for herself.
Nadya's Codex is a special codex created by a Grand Coven witch by the name of Nadya. Nadya was a gifted witch who had a knack for cracking coded texts, however Nadya was also selfish, once she cracked a code she then coded its secrets for herself, making the codex damn near indecipherable to anyone else. Nadya was hunted down by the Men of Letters, and had her life's work -- including the codex taken away. When Cuthbert Sinclair found out about the codex, he implemented a plan in secret to make sure that the Grand Coven could never get their hands on the book again by creating the Werther Box. The codex remained in the Werther Box until Sam Winchester came looking for it and was able to retrieve it.
In order to decrypt the Book of the Damned and remove the Mark of Cain from Dean's arm, Rowena sends Sam to locate and recover Nadya's codex by searching through the Men of Letters' files. Sam is able to find an audio recording of Cuthbert Sinclair's expulsion from the Men of Letters. Magnus developed the Werther Box: a safe with a deadly magical alarm system that causes almost everyone in the vicinity to commit suicide. He did this in order to prevent anyone from the Grand Coven from retrieving the codex, but Magnus was expelled as a result and the box was left in the St. Louis chapter house in perpetuity. It was supposed to have been guarded until Abaddon massacred the entire American membership in 1958.
When Sam makes his way to the Werther box, he attempts to use a spell recommended by Rowena to break the spell on the box, but it fizzles out before he opens it, making Dean, Suzie, and himself see vivid hallucinations. Sam's hallucination of Rowena helps Sam learn of how to unlock the box, giving it the blood of a Man of Letters or a Legacy, enough to take a life. Sam slits his wrist and tries to open the box himself, but Dean snaps out of his hallucination and stops Sam from killing himself. Dean offers some of his blood to slake the box's thirst and open the box and recover the codex.
While flipping through it, Sam tells Dean that he initially has no idea what he's holding, keeping the truth about the codex from Dean. The next day, Sam brings the Book of the Damned and the codex to Rowena at an abandoned brewery where he chains her to a post until she gets the cure for the Mark from the book before destroying it and killing Crowley to satisfy his end of the bargain.
A few days pass and Rowena hasn't been able to make any progress in translating the book. She explains to an angry Sam that when Nadya, a gifted and selfish witch, cracks a code, she uses it to encrypt her codex to keep its secrets to herself. Seeing that the decryption process has become paradoxical, Sam calls Charlie to help expedite the process of decrypting the codex and the book and Castiel to keep an eye on Rowena while Sam works on a case with Dean involving the Styne Family, the book's previous owners.
Charlie takes pictures of the codex and the book and runs them through her computer, searching for a pattern in the book's coding and any synchronicity with the symbols in Nadya's codex. Unfortunately, progress is stalled when Rowena and Charlie start fighting. When Castiel drags Rowena to a separate room so Charlie can focus, Charlie sneaks away to a nearby motel in order to run any pattern she can think of and running it through her computer. Eventually, she is able to find out how to decrypt both the book and the codex and sends the code breaker to Sam, but Eldon Styne manages to track her down and kill her.
Sam recieves an e-mail from Charlie containing the code breaker. With it, Rowena can translate the book and find the cure for the Mark. However before she recovers and provides the cure to Sam, she demands that Sam kill Crowley first, not knowing what will happen when the Mark is removed. Unfortunately, Sam's attempt to kill Crowley fails.
Rowena decides to make another deal with Sam. In exchange for removing the Mark, Rowena wants her freedom guaranteed and the codex. Sam accepts. She then gives Sam and Castiel a list of ingredients for the spell. Castiel is able to convince Crowley to provide everything and Rowena manages to cast the spell to destroy the Mark. However the blast from the spell manages to break the iron shackles keeping Rowena captive and her powers are strengthened because of the book's influence. She casts an attack dog spell on Castiel and compels him to kill Crowley and escapes with the Book of the Damned and the codex.
After capturing Rowena, Sam and Dean manage to find Nadya's codex and Charlie's code breaker in her suitcase. They also make a deal to remove the attack dog spell she cast on Castiel in exchange for her freedom. Later when she escapes, Sam says that the Book of the Damned would have been lost if they killed her and acknowledges that recovering the codex and Charlie's code breaker will keep Rowena from translating the book.
Rowena is captured and taken to the Needham Asylum where Crowley and the Winchesters ask for her help in dealing with the Darkness. When Rowena agrees to a deal to summon Lucifer in Hell in exchange for Crowley calling off his demon assassins, she asks for the codex and Charlie's code breaker. She is seen in the Bunker's dungeon looking through the book, the codex, and the code breaker to find the correct spell along with warding sigils to nullify Lucifer's powers.
- In later seasons, Rowena is shown to be capable of reading the Book of the Damned without the codex or the code breaker.
- It appears that the codex is encoded in saint symbolism given Charlie's comments in 10.21 Dark Dynasty as she tried to crack it and succeeded.