A devilish letter written by a 17th-century nun has finally been translated.

Sister Maria Crocifissa della Concezione, a 31-year-old nun at the convent of Palma di Montechiaro in Sicily, was believed to be possessed when she wrote the letter. On August 11, 1676, she was discovered on the floor of her cell with her face smeared with ink, clutching a letter filled with a strange mix of symbols and letters. Historical accounts suggest that Sister Maria claimed the letter was from the devil, attempting to turn her away from God and towards evil.

The 14-line message had puzzled scholars for centuries. However, recent advancements have led to significant breakthroughs in its translation.

Daniele Abate, director of Ludum, told Live Science, “When working on historical decryption, you cannot ignore the psychological profile of the writer. We needed to know as much as possible about this nun.”

Sister Maria entered the Benedictine convent at the age of 15, dedicating her life to God. Abate explained, “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.”

Researchers employed software to scan shorthand symbols from various languages, discovering that the letter contained elements from ancient alphabets such as Greek, Latin, Runic, and Arabic. Abate noted, “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. We thought we could just come out with a few words making sense. But the nun had a good command of languages. The message was more complete than expected.”

The letter, in addition to calling the Holy Trinity “dead weights,” included the statement: “God thinks he can free mortals. The system works for no one. Perhaps now, Styx is certain.” In ancient Greek and Roman mythology, Styx is the river separating the netherworld from the world of the living.

Abate believes the letter indicates that Sister Maria was suffering from mental health issues. He said, “The image of the devil is often present in these disorders. We learned from historical records that every night she screamed and fought against the devil.”