Attempt to hail a hostile ulthork. Kill it. Not all Ulthork qualify, look for those with a quest feather, target and hail(H or /hail). Note that you might not likely find a hailable Ulthork or one with a quest feather. Instead, head to ( 4376, -1079, 1160 ) and kill the Ulthork on that rock - that will update the quest.