On completion of the Bloodskull Disruption quest, speaking to Rainus again, he will offer you this quest. It is simply a quest to run to the Crossroads in Common Lands and speak to Captain Feralis. He is in the tower in the Crossroads compound at -428, -44, -281 .
On speaking to Feralis you will complete the quest getting 45 faction points with The Freeport Militia.
Continuing the conversation line (or going away and coming back and speaking to him again), he will offer the quest Filling The Coffers.