Actually, I lost that game. I mean, not that encounter, but the quest.
When zombies came closer Indian girl killed most of them with a hatchet, and I just went past them and finish the Corps pile so it can't spawn more of them, then finish the rest with a gun. We even had a cave-in during a fight, but nothing happened to us.
Problem was that later we got ambushed by tentacles, lost too much health, then immediately got attacked by some monster bats, while activating another zombie ambush, but this time with 2 digit number of them (12!), and when I saw we are going to die, I chose to flee from the cave, which is a fail for scenario, but at least you get your characters alive.
We got some XP, but not enough to advance up the levels. So, for now we are in town, healing and buying supplies. And town also has some quest... We, will see. :}