The Forge Master's Prize is a quest in Tyranny.
Bleden Mark told you about the Magebane Helm, an artifact created by the Forge-Bound Master Zdenya. Zdenya has recently arrived in Lethian's Crossing, and he mentioned to you that if you were to acquire the Helm, you would have the fear of those who call Lethian's Crossing their home.
- Head to Lethian's Crossing. Kill the Disfavored or Chorus garrison that's present at the location; the Bronze Brotherhood garrison should not disturb you if you didn't attack Raetommon at Ironhaul Trail.
- Enter The Forge and talk to Zdenya. You can use Athletics or Subterfuge 47 to try and pry the Helm away from you.
- Leave. Assault on the Crossing starts. The quests automatically ends when you find Zdenya taken captive.