Sixth-grade teacher Deborah Court thought the old book in the school's safe was just another dust-covered manuscript, but it turned out to be much more.
Court accidentally discovered a 340-year-old bible in the basement of the Lutheran school where she taught, according to researchers.
The Bonduel, Wisconsin church was stunned to learn of the book's importance.
While searching for old baptism records to show her students the teacher came across the 1,500 page manuscript, which is a copy of Martin Luther's translation of the Bible. The book seems to have been printed in Germany around 1670.
Timothy Schoup, the church's pastor, sent images of the book to Concordia Seminary Library in St. Louis, according to Yahoo News. After reviewing the book, researchers said it was one of only about 40 copies thought to be in existence.
Schoup told the AP that he had no idea how the Lutheran church/school, which will turn 150 in 2013, came in possession of the Bible.