From the introduction:
The Lost Codex is a strange and ancient legend that many talk about, but that few have had the opportunity to browse for real. Comprised of sheets held together by a string of thorns and existing in a single copy, it is kept in a trunk buried in the sands of the Whispering Desert, and its pages contain secrets and knowledge of all kinds, often insane and disturbing. The few who have been able to leaf through it tell of having come across disturbing pages, in which they found descriptions of alien creatures, remedies for the decomposition of flesh and spirit, sheets upon sheets full of diseases that can be contracted with the touch, representations of incomprehensible, illegible and impossible to replicate languages , illustrations that change as you look at them, stories of expeditions that ended badly or started in total desperation.