Returning to the Source
DISCLAIMER: Your Steps and Tasks may be different
You are given this Quest as part of the Returning for More Quest.
1) Reeni in Ardagh gives you a sealed scroll and asks you to talk to Sarena in Innis Carthaig. Sarena can be found in the stone building to the right of the stable master in Innis. She's wearing red and black and is a Poison Merchant. She'll ask what does Reeni want? Give her the scroll, and she'll say that Reeni's lucky she's already written down the information and hands you a sealed scroll to give back to Reeni. Take the scroll back to Reeni in Ardagh.
2) Give the scroll to Reeni, and she'll mutter that that information wasn't quite what she had expected, and that she needs you to take another scroll to Jarlath in Tir na Nog. She hands you another sealed scroll, and tells you to look for him in bars.
3) Jarlath can be found in /loc 21922, 26412, 7807 which is best accessed through the North Gate to Tir na Nog in Connacht. Go straight through the double gate to the building directly across, the one containing the healer Waljan. Just up the stairs is Jarlath. Talk to him. He'll give you another sealed scroll and tell you to find Tethra in Ardee, and talk with her.
4) Tethra is in /loc 54819, 51598, 5216 Connacht, in the main stone building (I think. I finished this very late at night and my memory is kinda foggy). Give her the scroll and I believe you are done. Head back to Reeni.