When you kill the Dogs, there are leaves that are left behind from the each kill, floating around in the air. Below the Office where Pack is located, there is a big empty glass bottle on a table with the sign, "The Leaves of Hell Spawn Will Spring New Life". I tried killing the dogs by this bottle, hoping the leaves would fill the bottle, but it didn't work. I tried killing the dogs with a Flesh Wounder and the Cannon weapon, still didn't work. It could be the dogs must be killed somewhere else, the leaves will be collected there? Not sure. Anyone else have any ideas about this being a possible EE step? Or it could be this step has to be done in order.