Elf in E8.
Makes you invisible to enemy.
+3 for talking to Elf, -3 for giving away ring.
Talk to Elf in E8. Keep in mind the Elf isn't always there, so you may have to come back a few times.
The ring will last a limited amount of time. Don't wear the ring when you don't need it. The wolf can also get you if you are wearing the ring and you get too close to him (he can smell you). The sorcerer also isn't stopped by the ring.
The magic ring is a gift from the elf and it will make you invisible while you wear it. This is useful in a number of places, such as around the Dragon, Giant or any of the areas enemy's show up. To use it, click the ring on yourself. You will stay invisible until you take off the ring (by clicking it on yourself when you are wearing it) or until the ring runs out of time. It lasts about 60 seconds, depending on the game speed.