Behind the Great Veil

Behind the Great Veil is a book in The Witcher 3: Wild Hunt.

Content
''Of the many demons which reside in the outer spheres, hyms are among the most dangerous. Other demons usually must take on concrete living form - be it of man or beast. Hyms, on the other hand, appear in our world in their own immaterial form, which is invisible to all save their chosen victim.''

''Hyms feed on fear, regret, a sense of guilt - in a word, on negative emotions, and since they are eternally hungry, they provoke these emotions in the humans they torment. These demons cannot be exorcized. A man a hym takes as a victim is lost and will inevitably succumb to madness, and then death.''