The Vanishing of Ethan Carter

This is the final scene investigation achievement, which begins inside the dam control building.

From the end of Bargaining achievement move to the back of the middle control to find a wheel that can be turned. Turn it using X to alter the dam so you can cross the water.

Leave the dam control building by moving the lock on the door and make your way across the stone bridge that is now available. Take a right after leaving the bridge and follow the path to a stream and eventually, a lake. Head around the lake to the burnt remains of a house. Go inside, through a door where you'll be greeted by a floor puzzle. Move to the back of the puzzle and turn the orbs to spell out C-O-R-V-U-S clockwise from the metal pole.

Head downstairs and inspect the body to begin the sequence of orbs. Once all 4 have appeared after moving close to them, you will need to tag them in the right order and hit visualise with the Y button to watch a scene before following a blue orb to the final scene and the achievement.

Below is a step by step guide to obtaining the achievement.