Quick Chapter 9 Influence Grind.

For grinding chapter 9 influence you have two options. The first option is the zombies in the town right above the fork in the river in the south-east section of the map, or the forest of shadows which is located directly west of it. The town is a good place to grind, if you are level 18 or higher. Below that level, I suggest going to the the forrest of shadows.

The forest of shadows has two kinds of mobs, a 'Gor raider', and a boar with hundreds of horns. They are both level 17-18, which is a little easier to fight if you haven't yet made it to a point where fighting 1-2 level 20 zombies is an appealing idea. The tier 1 of this public quest is "collect 40 boxes of supplies." Each box is worth 100 influence. The boxes respawn very quickly, sometimes one will respawn while you're picking up another one. If there is no one else in the area you can farm about 4000 influence in about 5 minutes. Wait till the timer resets and do it again. I suggest heading over to the zombie area if you're at a loss for things to do while you wait the 10 minutes.

As you can see from this screen-shot; you can be pretty far away from those boxes when you loot them. However there are some infrequent patrols that like to sneak up on you so check behind you from time to time.

Good luck with the grinding, I don't know what all the rewards are, but I got a very decent weapon out of the deal.