- Talk to Gardel. He'll be rude to you.
- Ask the girl right beside her about Gardel's weakness.
- Obtain Dullahan's Tear or Dullahan's Sign from Dullahan (head, body , or the whole thing). Use it to threaten Gardel.
- Obtain information about the Unholy Sword, and get Gardel's Receipt from him.
- You can also do this quest without finishing Wilphson's Receipt Quest to do the quest Gardel Time Travel Medicine