This is a Qeynos Bounty quest to raise faction with Qeynos for Citizenship.
Talk to Gil McMartin in Commonlands. He sends you into West Freeport to kill Atraxas Bhotlis, who spawns near 281,-3.9,88.5 as a single up arrow mob at the quest holder's level. Use the Freeport sewer system for easier access to West Freeport.
Once dead, return to Gil in the Commonlands to collect your bounty.