At level 2 of Lighthaven temple dungeon you will find Undead Bats.

Kill them until you find Decaying Bat Wings. Take them and go to the Lighthaven mage tower (North-East from Lighthaven, follow the pathupwards).

There you will find an NPC named Uranos. Say Work to him and he will tell you about a component that he needs.

He will also tells you to find Marsac Cred and ask him about the component. Go to Windhowl town and find Marsac Cred (he is at Uranos to him.

He will say that the component is Decaying Bat Wings.

Go back to Uranos and say Decaying Bat Wings.

Gain:

• 2,500 XP
• Skull dagger

Note 1: You can say “Decaying Bat Wings” directly to Uranos (it isn't necessary to visit Marsac Cred)

Note 2: There is a chance that Uranos will not take the wings. That happens because someone has done the quest recently. If this happens to you, leave and return to Uranos later.