The weapon wielded by the Mord Sith in Terry Goodkind's Sword of Truth series.
The agiel appears to be a simple leather rod. However, when in the hands of its Mord Sith, it can be an instrument of pain and suffering. The Mord Sith can use it to inflict great pain on her intended victim and can even break bones or cause death if she wills it. It is a simple mundane object if anyone picks it up other than the Mord Sith to whom it is bonded.