Researchers have found pages of a rare medieval manuscript masquerading as a cover and stitched into the binding of another book, according to experts at the Cambridge University Library in England, CNN reports.

Rather than risk damaging the brittle pages by removing the stitches and unfolding them, a team of researchers were able to conduct imaging and computed tomography—or CT—scans to create a 3D model of the papers and virtually unfurl them to read the story.

The scans revealed book-binding techniques from the distant past and hidden details of the repurposed manuscript that could shed light on its origins.

The fragment contains stories about the wizard Merlin and King Arthur. The two pages are from a 13th century copy of the “Suite Vulgate du Merlin.” The manuscript, handwritten by a medieval scribe in Old French, served as the sequel to the legend of King Arthur. There are just over three dozen surviving copies of the sequel today.

Part of a series known as the Lancelot-Grail cycle, the Arthurian romance was popular among aristocrats and royalty, said Dr. Irene Fabry-Tehranchi, French specialist in collections and academic liaison at Cambridge University Library. The stories were either read aloud or performed by trouveres, or poets, who traveled from court to court, she said.

Fabry-Tehranchi said finding it “is very much a once in a lifetime experience.”