To start this quest you should go to Dark Cavern, kill Real Trompdoy (lvl 5) and loot Band of Braccus from his corpse.
I felt a jolt of energy when I picked up Trompdoy's ring. It wants me to put it on...
The Cursed Ring
Related points of interest
Quest stages of The Cursed Ring
1. Curse Apply
Put on Band of Braccus. It will curse you! (-10% to accuracy and dodging; -15% to resistances).
I put on Trompdoy's ring, only for it to curse me.
2. Take Off
Unequip the ring. It won't remove the curse!
I discovered that removing the ring did not lift its curse. I must find it a new host...
3. Remove Curse
You need to cast Bless skill on yourself. If you don't have that spell yet, then you need to visit Your God in Halls of Echoes.
I have removed the ring's curse... best not put it on again.
4. Move To Next Category
If you left the island without removing the curse.
I have left Reaper's Eye, still bound to the ring.