This is number 15 in a series of 16 bounty quests.
This is a quest offered by Gol M'Tun to gain faction with Freeport when you are exiled.
Kill Nor'sona A'tyel, who is a triggered spawn at 525, -18, -418 near the entrance to The Down Below in the Elddar Grove, Qeynos Province District. There is an epic guard who wanders somewhat close to here, so don't stray very far.
Finish the quest by talking to Gol M'Tun again.