This is another Qeynos Bounty quest to gain faction with Qeynos for Citizenship.
It is given by Gil McMartin in the Commonlands. He tells you to travel to Antonica to kill Smithe Bluth, who roams in the farmlands of Northern Antonica between -1860, -20, -330 and -1,901.96, -18.75, -249.04 on the grounds of McQuibble's Farm.
Smithe will spawn at the level of the questholder as a solo mob. Kill him and return to Gil McMartin in the Commonlands to collect your bounty.