Off the Rails is the final mission in the series before you can finally start your own Acid Lab business. This mission is quite combat-heavy, stock up on armor and snacks before starting this mission.
First, make your way to Humane Labs. Once you get there, you have two options. Either go in loud or sneak your way in. Both are viable options. However, the stealthy approach, in this case, is faster.
When you get to the entrance of Humane Labs, ensure you've equipped a suppressed weapon. Also, avoid the enemy's cones of vision on the mini-map to stay undetected.
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You will find a single security guard at the entrance. Take him out with a headshot.
Go a bit forward, and you will find a security camera at the corner of the building. Shoot it to destroy it. If you cannot pinpoint the camera's location, refer to your mini-map, as it shows the cone of vision.
Stay on the left side of the parking lot and continue moving forward until you reach the middle.
Look to your right, and you will see some stairs and a guard at the base of the stairs. Take him out with a headshot and go up the stairs.
When you're at the top, look to your left, and you will see a couple more guards. One will be patrolling the area while the other will be stationary. Wait for the patrolling guard to go a bit further ahead, and take out the stationary guard with a headshot.
Move up and take out the guard in the distance standing by the keypad.
Wait for the patrolling guard to start walking toward you. When you have a clear shot, eliminate him with a headshot. Doing so may alert the staff member standing on the left. Quickly, take him out with a headshot before he alerts the rest of the guards in the area.
Finally, a guard on the platform will be directly in front of you, walking back and forth. Wait for a clear shot, and eliminate him as well.
Continue moving forward, and before you approach the keypad, take out the security camera directly above it.
After taking out the keypad, you can interact with the keypad to hack it and enter the facility.
Upon entering the facility, try to walk slowly. Move up deeper into the facility, and first, take out the security camera to your left.
Then before moving forward to the loading bay, quickly take out both the guards in front of you with a headshot.
As you pass through the wide doorway, look to your left, and you will see another guard.
Walk to the right side, and look in the distance to find two more guards. Take them both out, and the loading bay will be clear.
You now need to find the inventory manifest and take a picture of it. The manifest can spawn on the wall in two possible spawn locations.
Manifest Location 1
On the wall to your right after going through the wide doorway.
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Manifest Location 2
On the wall to your left next to the wooden crate and a stack of cardboard.
Once you've taken the picture, send it to Dax.
After that, you must search all the wooden crates and collect chemicals. You need to collect five chemicals. Some of the wooden crates might not contain the chemicals, so go through them all until you have all five chemicals.
Once collected, it's time to leave the area. Shoot the power box to open the shutters.
There will be a vehicle outside that you can take to the next location.
You must make your way to the train switching station before the train carrying the chemical reaches the station.
Exit Humane Labs, and keep driving until you see an opening to your left.
Go through the opening and onto the train tracks. Keep following the train tracks to reach the switching station.
Head inside the switching station, and pull the lever to change the tracks and cause the train to crash.
After a mini-cut scene, you need to get your hands on a cutting saw. You can easily get it from the worker's tool bag just ahead of you.
Drive a little further ahead, and a green bag appears on your mini-map. You will find two workers standing by the tool bag.
Eliminate the workers, and steal the cutting saw from the bag. This cutting saw is required to open the containers at the train crash site.
Once you have the saw, make your way to the train crash site and open up the containers. They are marked by a white circle on your mini-map.
Take your time to take out enemies while staying taking cover. You're not on a timer.
Although you don't need it, if you have a launcher, it will make your life much easier. You will constantly get attacked by enemy choppers and can use your launcher to take them out quickly.
It is still okay if you don't have a launcher. Just wait for the attack chopper to get closer and shoot the pilot to take it out instantly.
Get on the trailers and interact with the container to cut it open. If there is a chemical inside, it will have a green hovering arrow on top. Approach the chemical, and interact with it to collect it.
Stay covered and use the containers to your advantage. It provides great cover against attacking enemy choppers. Clear out the enemies before you start opening the containers as you enter a small cutting animation that cannot be canceled.
You will die if you're in direct sight of the enemy during the cutting animation.
Once you've collected all the chemicals, go to the end of the crash, and steal the Brickade 6x6 truck.
Drive this truck back to The Freakshop to complete this mission successfully.
With Off the Rails complete, you've finished The First Dose mission series and can now set up your very own Acid Lab business.
Mission Accomplished?
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