The Pits!

The downpour of rain was worse than they thought it would be. Allison was called in despite the rain because the pits were flooding.

Allison was given a raincoat so she could move freely in the rain without any worry of getting wet.

They rushed to the pits and saw that it was filled with zombies. It had only been a couple of hours so they were surprised why there were so many zombies.

It was almost like they could smell them, Allison wasn't worried because the kind of zombies that had filled the pit were the typical ones.

The weakest of the weak, they could handle them.

The pit flooding meant that they would be washed up to the surface, this was the flaw in their defence system but even with that, they couldn't scale their defence.

Allison was given a spear, this allowed her to strike from range without letting them come too close.