Elfbark is a herb that Fitz uses to make a strong, black, bitter tea that helps him to dull his Skill-hunger as well as help the Skill-headaches that he has after Skilling. Kettle was horrified when she found out Fitz was using it, for it is said to extinguish the ability to Skill in the young and cripple its growth for older Skill-users. Fitz's experience is that it can deaden the ability to Skill, but it doesn't kill the craving for that connection. In Chalced it is used to drug the slaves, for it increases stamina but dulls the mind, so that the slaves don't try to escape. The low mood and morose spirit it gives is very familiar indeed to Fitz. It is said that the use of it can become a habit, but Fitz reflects that perhaps that only happens when the use of it is forced regularly.