Note: There are two Trophies/Achievements that can be unlocked throughout The Ghost Survivors chapters.
Get To The Meetup Point In The Sewers
Once you begin the mission step inside the Gun Shop and collect the Police Radio Recording from the shelf to the right and shoot the Raccoon that’s sitting on a shelf in the southwest corner. Head outside where you’ll come across a couple of Poisonous Zombies.
You’ll want to take the poisonous Zombies out from a distance because when you kill them, they will explode into a poisonous cloud which will make you alot slower if you were to get caught in it.
Once you’ve dealt with the two poisonous Zombies, make your way down to the Parking Garage, shoot the Zombie with the explosive tank on him and then head down the manhole to the Sewers. Make your way across the bridge, shoot the Zombie’s legs so the explosive tank drops to the floor and wait for the Licker to be near it before shooting it.
Continue forward until you see a Zombie with a Backpack, shoot it to retrieve some items and sprint along to the Undeground Stairs.
Note: You’ll be able to sprint past the Zombies that are currently getting up.
Head downstairs and take the Explosive Zombie out, use the Item Dispenser and take the Flash Grenade, go through the door and take out the Zombies with the Shotgun before using the lift to the Worker’s Break Room. Exit the room and shoot the Zombie with the bag to gain the Stun Gun, then head right to the Work Room, use the Lift to head down to the Lower Waterway and stun the 3 G-Type Adults to get past.
Climb the platform and take out the Ivy, continue onwards to the Control Room, circle the Zombies and drop down to the Monitor Room. Take out the Ivy and head through the door with the Keep Out Sign above it. Head downstairs and follow the path around to the Main Power Room, shoot the G-Type’s eye with the Shotgun to stun it and sprint past before using the Flash Grenade to stun all the enemies and sprint through them all to the end.
Note: You may need to use the Shotgun to stun the Ivy that may try to attack you as you head past.