Tier 1: Follow the Snake
After the discussion with the quest giver, go outside and click on the Python. He should be relaxing next to the plant on the left hand side of the entrance. Now it’s time to play follow the snake! It will slither off and head to the marked location on the map. So even if you lose the snake, you should either be able to go back and get another one, or just go to the meeting spot yourself.
Tier 2: Examine Corpse, Kill Ambushers and Follow the Wisps
Once the snake reaches its destination, you will be required to look at someones corpse. When you do, be prepared to be ambushed. Fight them off and proceed to follow the spirits of the departed.
Tier 3: Prevent Cultists from Completing the Ritual
You trace the spirits to an alter, it is your job to destroy said alter. Clear out the enemies and proceed to blow it up before moving onto Tier 4.
Tier 4: Move Deeper into Camp and Prevent Cultists from Completing the Ritual
Continue up the path, killing things along the path. After a few groups you will come across an alter surrounded by green lights.
Tier 5: Demolish Ritual Alter & Destroy Caahs the Soulspawn
Clear the surrounding area and kill Caahs the Soulspawn and destroy the final alter to finish this mission.