From Below

Tier 1

Objective: Get into position to defend the camp

Line up with the other Orochi soldiers and get ready!

Objective: Defend the camp until the attacks subside

There will be multiple waves of filth spawns. You can activate one turret at a time to help taking them down faster.

Objective: Clear the area of infected Orochi

Objective: Find and kill the leader of the attacks

Head south to the base of the filth infected Orochi, then defeat 5 of them.

The leader can be found on the top of a cliffside. He is guarded by two Fortified Carriers. All of their attacks are mainly ground AoE based so the fight shouldn’t be too hard.

Tier 2

Objective: Go into the Ankh chasm

Head to the location pinpointed on the minimap

Objective: Clear the area of Bloated Orochi

Objective: Clear the area of Filth Infectors

The Bloated Orochi will not attack you unless you do so. They can suddenly start the process of spontaneous self-combustion, something you can take advantage of. You will need to defeat 8 of these.

The Filth Infectors are pure black and creeping creatures with yellow eyes. You will have to kill 2 of these monsters.

Tier 3

Objective: Investigate the plateu

Ascend the mountainside and enter the experimental facility area.

Objective: Clear the area of failed experiments

Simply kill 5 failed experiments in the area around the large tent. You should examine each monster before attacking them. Some are really easy to kill while others… not so much. There is even one monster there with 12 million HP.

Tier 4

Objective: Enter the tent

Head inside the large Orochi tent to advance the mission

Objective: Kill Dr Shirui

Objective: Destroy Experiment SB118

Both of these are inside the tent and they are pretty close to each other. Finish them both off to complete the mission!

You may want to pick up the side mission Primum Non Nocere while there.