Get in the factory through the sewers. Go right to the first fork after jumping down.
Go into the lab, retrieve the Water Sample from the machine, go down stairs to use it on the flashing device.
Finish the water sample puzzle to unlock factory lock. Go back out to the sewers and got to the end for the door.
Go up the stairs and clear the enemies here. Move up the elevator to control room.
Clear out the zombies in the control room, picking up a System Disk on the desk and a map next to the door out.
2. Match The Graph To Clear Water Sample Puzzle
To pass the water sample puzzle, you'll need to align the 3 rows to have their shape stack to the formation at the bottom (Kind of like tetris). Here's a simple tip:
How To Solve Water Sample Puzzle Fast
Find the 3-column lines and empty lines.
Align the rows to match the 3-column lines and empty lines.
Twist & tweak the rows until it fits.
Remember The Key Machine
You'll find a key machine here next to the water sample machine. Keep a mental note on it as it will open up a huge arsenal for you later.
3. 2 Stash Of Shotgun Shells In Carts
2 sets of Shotgun Shells can be found in the carts next to the Bio-Hazard Pool. Clear out the Stingers, zombies or Hunters to get them.
Sewer To Control Room
Sewer To Control Room Walkthrough Chart
Go out to the corridor, taking the east door into the safe room. Take the Facility Key.
Go out the door to the steam control room. Solve the steam reroute puzzle to unlock the door to Bio-waste treatment.
Go back to the safe room, stock up for a boss fight.
Backtrack to the control room, killing Stinger/ Hunter along the way.
Go through the east door to Bio-waste treatment, beat Nemesis. There's a time limit starting now.
Pick up the Card Key after beating Nemesis.
Optional: Bring the Facility Key back to the water sample key machine to be reprogrammed. Head back to the steamer control room, use the Card Key to use elevator. Find Rocket Launcher in a hidden armory.
Use Card Key to unlock the sliders to the helipad. Dispatch zombies, then pick up Radar Receiver. Nikolai will appear in a gunship.
Choose to fight him or negotiate. Fighting him will end him for good.
Go down the ladder, taking out 2 zombies in the way. Head over to the Rail Cannon room.
Beat Nemesis (Final Form) by luring it to the Rail Cannon's line of fire.
Go out the door to the right, watch the ending cutscene.
2. Solve The Steam Puzzle To Access Bio-waste Treatment
The steam puzzle requires you turn off/on valves until you can get to the control panels that will unlock the path to Bio-waste treatment. Bio-waste treatment can then be accessed from the control room.
Steam Puzzle walkthrough
Get to the southern end.
Press the 2 buttons there.
Move up to the northern end.
Press the 2 buttons.
Activate the controls
3. Getting Ready To Fight Nemesis
You will be fighting the Nemesis when you progress from here, as well as Stingers and Hunters in your way.
Shooting at the dispensers on the wall will spurt acid, which will cause massive damage to Nemesis if it manages to hit. Pre-aim one and shoot at it when Nemesis enters the Acid's range.
7. How To Beat Nikolai
Nikolai's chopper will surround the building, firing inaccurate rockets. Shoot at it with your magnum, or blow it up in 1 shot from your Rocket Launcher.
HowTo Beat Nemesis (Final Form)
To beat Nemesis (Final Form), you have to let it take 2 ~ 3 Rail Cannon hits. You can deal damage to it where it will go back to a corner, guaranteeing a direct cannon hit, or bait it to come to the cannon's line of fire.
Nemesis (Final Form) Flowchart
1. Push in Battery 1
2. Nemesis appears, go push Battery 2.
3. Push in Battery 3 next to cannon.
Lure Nemesis by shooting at it near the blasted hole.
Fire at it with everything you got to get it to eat the tyrant.
Use Your Rocket Launcher To Speed Things Up
Rocket Launcher greatly reduces the time it takes to get nemesis to go for a chow-down. Freeze rounds/ Magnum are still effective as always, so use everything you've got.
Start A New & Improved Playthrough After Ending!
You get a new mode for you to earn secret weapons as well as new costumes after the end game roll! Go start a new playthrough with an advantage!