The Siren's Cadence
The Siren's Last Cadence
This Quest is recieved to you by talking to Nessa in Lioneye's Watch after entering the Cavern of Wrath. If you go visit Nessa now she will give you the reward of a Support Gem or alternatively upon entering Merveil's Lair and requires you to kill Merveil the Siren (entrance from The Ship Graveyard -> The Coves -> Cavern of Wrath -> Cavern of Anger -> Merveil's Lair.