This big old book is in the censored section of the library of Principal Island, as it contains information about the legend, wich is forbidden to talk about. Twinsen gets to read the book by asking the rabibunny who works there about the legend, and there he learns that he has to go to the White Leaf Desert to learn more about it.
"In the distant past, when the spheros, rabibunnies, Quetches and grobos emerged from the original primordial soup, centuries before Dr. FunFrock's coup, a prophecy was pronounced. Its text is hardly remembered today and that is why people now refer to it as the "Legend". It explained how "the Heir," when his time had come, would be called to overthrow a tyrant! The secret of the Legend can still be learned somewhere in the White Leaf Desert."