An awl under your foot (Castle)

We talk with Supervisor of Underground Prison and take the quest.
Three groups of monsters were spotted in the dungeon under the abandoned Castle. You need to kill their leaders and bring back the Dungeon Leader's Sign. In this case, the Guardian will give you the Knight's Epaulette, which will allow you to make transactions with the Castle merchants.
Go to the fortress dungeon. Kill the monsters.
Receive Sign of Leader of Cave