The hierophant asks Geralt to get a psilocybe mushroom so he can lure the remaining Salamandra into an ambush. Apparently this would make fisstech even more powerful than it is, so it makes for a very good bait for the planned surprise attack. This must be the distilled ingredient. This item is never found in the game, it is only described in a journal entry. Only the mushroom itself — Image:Quest Items Psilocybe mushroom.png — is a "concrete" game item.