Nil

Wheloon Prison
Nil can be found randomly around the prison. She gives you a key to a locked room in Shar Manor, and asks you to retrieve some documents.

Detour
While you fight her, she will narrate the events of the battle as if she was in a story:
 * Nil: 'Tis but a scratch, the bard exclaimed. She wasn't about to let the filthy mongrels foil her mission.
 * Nil: The bard's health was failing her: the pain almost too much to bear. But, the pain of failure would sting more, so she fought on.
 * Nil: Her blood painted the battlefield. It was beginning to look like the bard's opponents would indeed slip away from her.
 * Nil: In an unexpected turn of events, the Bard exclaimed, Stop! Don't kill me, I give up!

After her defeat, when you talk to her she will reply:
 * Nil: I know you don't have much reason to believe me, but I'm on your side. I had to attack, so as not to blow my cover. Unfortunately, my disguise worked a little too well, and not even your friend Bensen recognized me.
 * Nil: I'm the one that sold the information about these mercenaries to the Harpers. You and I have no qualm. I implore you to let me go.
 * You: Very well, go. I can see you pose little threat anyway.
 * Nil: Thanks.
 * You: Do you have any more information for us?
 * Nil: Not much more than you already know. The Netherese are persistent. They're searching far and wide for the other pieces of the Nether Scroll, and they won't give up easily. You didn't hear it from me, but they've taken over Granwell Keep and are using it as a base of operations here in Cormyr. That's about all I know.
 * You: Thanks, and sorry about the trashing.