The books were found almost by accident. An annex, known from the Ages#The Golden Age, had been sealed early in the library's history, to protect the valuable books within from the first public access to the library. During the Fifth Age, researchers looking for the annex had to move several shelves. While the shelves had housed countless different collections in the public portion of the library over the eons, they were there when the library first opened.
Behind one set of shelves, the researchers found the Viverren Cache inside an old display case built into a support column. No other column had such a case, so no one had any reason to suspect anything might be there. No one knows when the library was last active before it was opened by Eieber in the early Golden Age, or why this particular collection of books was concealed behind shelving.
The books are all written in Viverren and appear to date from roughly the same time period. The collection contains books on every subject imaginable, including history, poetry, fiction, art, music, and even several volumes of scientific texts. There are books on tool-making and weapons crafting; love poetry; biographies; one volume is even believed to contain incantations used in Viverren magic.
The scientific books recieved the most wide-spread attention, as Viverren science was described as "cartoonish" and on the whole very bad. The books did, however, demonstrate a firm grasp of mathematics, and indicated that the Viverren even possessed a rudimentary form of calculus.
Three books called into question the authenticity of the find. These volumes appeared to be of higher quality than the rest: the bark was pressed and treated with resins; and, surprisingly, the text appeared to be printed. This would indicate that the Viverren, at one time, had such advanced technology as the printing press.
The book shelf concealing the cache was firmly secured to the floor and likely had not been moved for thousands of years. It was in a well-documented section of the library, wherein the shelf can be seen in paintings commissioned the day the library was opened. The earliest-known photographs if the library include that shelf. If the entire cache is a hoax, it must have been perpetrated before the Golden Age, before the Alliance.
Why, then, would someone from that era have gone to the effort of creating such an elaborate ruse? During the Mage Wars, Viverren were slaughtered as vermin, used as slaves, or sent into battle as expendable troops.
One possible explanation is that the books date from the Golden Age, but there is no documentation of a display in that location and no other historical evidence to support this. It is simply the only time in history at which irrefutable evidence for the book case does not exist.
Another factor in the books' favor: the bark used to make them comes from a species of tree thought extinct since the late Dynastic Period. If they are a forgery, they must have been forged much earlier.
Other Viverren Books
Nearly all extant Viverren books come from the cache, only around ten other intact, readable books have ever been found, and these were all discovered in museums or private collections. Viverren used a very soft, papery tree bark for their books, and typically lived in very wet climates where their books did not last long.
All other examples of Viverren text are found written or carved into stone walls. They may also have carved on tree trunks.
Some scholars believe that "Viverren books" are not Viverren at all, but rather belong to another, as yet unknown, race entirely. This theory has some merit, as modern Viverren are unable to read their own written language and scholars have no idea how any of the words sound read aloud.