On August 11, 1676, sister Maria Crocifissa della Concezione, a Benedictine nun with the Palma di Montechiaro convent in Italy, was found unconscious in her room, her face smeared with ink, with an undecipherable letter written in an unknown script clutched in her hand. Although she did not remember the origin of the letter, nor could she and her sisters decode the cryptic writing on it, they concluded that Sister Maria had survived a battle with Satan, having refused to sign a letter written by the demon denouncing her faith.

For 341 years, the contents of the letter have remained an enigma, until a research team from the Ludum Science Center in Sicily pitted the arcane script against an illicit code-cracking algorithm they discovered on the dark web, yielding a translation that begins to make sense of the letter’s secret.

"We heard about the software, which we believe is used by intelligence services for codebreaking. We primed the software with ancient Greek, Arabic, the Runic alphabet and Latin to descramble some of the letter and show that it really is devilish," explains Daniele Abate, director of the Ludum Science Center.

"The letter appeared as if it was written in shorthand. We speculated that Sister Maria created a new vocabulary using ancient alphabets that she may have known," Abate continues. "We analyzed how the syllables and graphisms [or thoughts depicted as symbols] repeated in the letter in order to locate vowels, and we ended up with a refined decryption algorithm."

The contents of the letter are apparently inconsistent and rambling, and concerns the connection between God, humans, and Satan. It claims that the Holy Trinity — God, Jesus, and the Holy Spirit — are "dead weights", and that humanity created God and Zoroaster. It goes on to say that "God thinks he can free mortals," and that "this system works for no one". It concludes with an odd and ambiguous statement, "Perhaps now, Styx is certain," referring to the River Styx, the river from Greek mythology that must be crossed by the dead to reach the Underworld.

The research team has concluded that Sister Maria devised the text, either knowingly or unconsciously, possibly as a result over possible spiritual difficulties she may have been suffering. "I personally believe that the nun had a good command of languages, which allowed her to invent the code, and may have suffered from a condition like schizophrenia, which made her imagine dialogues with the Devil," Abate concludes.

As for what the true circumstances surrounding the origins of the letter — fraud, illness, or demonic possession — we may never truly know.