Can't pass the quest \"a Change of consciousness\" (Gothic 2)

Help me to cope with the cross Change of consciousness and I gave Fortuno Green novice, the alchemist in the bandit camp I got the recipe and bought all the ingredients, give a potion and he dies. Tell me what to do in this situation? There (in the recipe) says that you have to learn two bloody stings of the flies something to do with them, if you know then write who need to learn.