Crumbling medieval texts do not usually make for the subjects of frenzied online debate, with the notable exception of the thoroughly bizarre, persistently impenetrable Voynich Manuscript. The text, written in a language that has yet to be decoded, has confounded scholars, cryptologists and amateur sleuths for centuries. And last week, a hullaballoo erupted over a Times Literary Supplement piece by historical researcher and television writer Nicholas Gibbs, who claimed to have solved the enduring Voynich mystery.

The manuscript, Gibbs theorized, is a woman’s health manual, and each character of its elusive language represents medieval Latin abbreviations. Gibbs claimed to have decoded two lines of the text, and his work was initially met with enthusiasm. But alas, experts and enthusiasts were soon poking holes in Gibbs’ theory. Lisa Fagin Davis, executive director of the Medieval Academy of America, told the Atlantic’s Sarah Zhang that Gibbs’ decoded text “doesn’t result in Latin that makes sense.”

The most recent interpretation of the Voynich Manuscript may not have been sound, but it’s certainly not the wackiest theory about the text’s contents and origin. The manuscript has been attributed to everyone from ancient Mexican cultures to Leonardo da Vinci to aliens. Some say the book is a nature encyclopedia. Others claim it is an elaborate hoax.

Why has the Voynich proved so baffling, so polarizing over the years? Here are six things to know about the elusive manuscript:

It is divided into four sections, each of them very weird

As Michael LaPointe explains in the Paris Review, the book begins with an herbal section featuring vibrant drawings of plants—but nobody is quite sure what sort of plants they are supposed to be. Then comes the astrological section, which includes foldout drawings of celestial charts that do not seem to match up with any known calendar. The astrological wheels are dotted with little drawings of nude women, and in the subsequent balneological section, the nude drawings go wild. Illustrations depict naked women bathing in green liquid, naked women being propelled by jets of water, naked women supporting rainbows with their hands. Some scholars believe that one illustration shows naked women hanging out on a pair of ovaries.

And finally, there is the pharmacological section. It includes additional drawings of plants, followed by pages of writing in the manuscript’s mysterious language, which has been dubbed “Voynichese.”

The manuscript’s early owners also found it very confusing

The Voynich first appears in the historical record in the late 16th century, as Davis writes on her blog Manuscript Road Trip. Rudolph II of Germany purchased the book for 600 gold ducats, believing that it had been written by the 13th-century English scientist Roger Bacon. It then passed into the hands of Georgius Barschius, an alchemist from Prague, who referred to the book as “a certain riddle of the Sphinx” that was “uselessly taking up space.”

When Barschius’ heir, Johannes Marcus Marci, inherited the manuscript, he sent it to an Egyptian hieroglyphics expert in Rome for help decoding the text. “[S]uch Sphinxes as these obey no one but their master,” Marci wrote in an accompanying letter, according to Davis.

The manuscript then disappeared for 250 years, only to resurface when it was purchased by Polish book dealer Wilfrid Voynich in 1912. Voynich refused to divulge the manuscript’s previous owner, leading many to believe that he had authored the text himself. But after Voynich’s death, his wife claimed that he had purchased the book from the Jesuit College at Frascati near Rome.

Some of the world’s most prominent cryptologists have tried—and failed—to decode the text

William Friedman, the pioneering cryptologist known for breaking Japan’s code during WWII, spent years trying to decipher the Voynich manuscript, according to the Washington Post’s Sadie Dingfelder. He ultimately concluded that it was “was an early attempt to construct an artificial or universal language of the a priori type,” according to LaPointe of the Paris Review.

Although its origins remain murky, “Voynichese” does not appear to be complete gobbledygook. In 2014, Brazilian researchers used complex network modeling to show that the text displays similar linguistic patterns to that of known languages. The researchers were not, however, able to translate the book.

The Voynich has been carbon dated to the 15th century

The testing, which was carried out in 2009, showed that the parchment likely dates to some time between 1404 and 1438. As Davis notes, these results rule out several individuals who had been named as authors of the manuscript. Roger Bacon, the English scientist, died in 1292. Da Vinci was only born in 1452. And Voynich came into the world long after the weird manuscript was written down.

Alien authors, however, remain a viable possibility.

William Shatner contributed dramatic narration to a "Weird or What?" episode about the Voynich manuscript

We’ll just leave this here.

The manuscript is available online, for your sleuthing pleasure

Yale’s Beinecke Rare Book & Manuscript Library, which now holds the manuscript, keeps it locked safely in a vault. Should you fancy taking a crack at the ever-enigmatic Voynich, a complete digital copy is available online. But consider yourself warned: the Voynich rabbit hole is very, very deep.