On PvE servers, this is a guide or GM-related event. PvP and Exchange servers may have this quest as a constant fixture.
Steps[]
Mudeye will let you know that his sister has been kidnapped, and ask you to find her.
The precise level range that will be offered the quest is unknown, but it's lower than 75. A group reported that they were offered the quest when they mentored to a level 39 character.
Mudeye's sister is Dumsel and will be hiding somewhere in the Feerrott.
Known possible locations include the Fear Camp near ( -1011, -6, 711 ) Copy/waypoint -1011, -6, 711 and the Alliz Tae Outpost.
Now it's just a matter of fighting your way back to the docks. Do so, and the Guide/Guides will talk about how much they missed each other, and give you a reward.