Amnesia: Rebirth

Story related:
You earn this after completing chapter "Portal Chamber 3rd visit"

Massive Tip - Turn Gamma to max!

Quick guide - No collectibles

Following on from the Somnambulist achievement you start standing up in a pretty messed up state again. Head forward going to the left and remove the bricks from the wall and head through. Take the right tunnel, pick up a brick with RT and throw it to break through with RB. Climb down and head forward following the paths and ignoring the glitchy wall until the you get to the dead end room. Here you will see a glitchy wall to the left so pull out your compass with RS and head through. Cross over the bridge and keep running as this is where the shadow can get you. Don't worry too much because if it does the respawn place isn't bad at all, sometimes it even progresses you a little.
Head forward, go left and take a right up the stone steps, forward and then down into the water. Go forward a little bit in the pool, press RS to pull out your compass and head left through the wall. Follow the clear path and when you see a wooden door on your right, take a left and run down the stairs. Head through the gaps in the wall and into the room with a fallen over pillar breaking the wall. Head down the ladder here, in the right far corner. Follow the linear path and when you come to a fork, take the left route up some stairs. Keep running through and when in the next room head to the right corner, quickly move the barrel and head through. Now just keep running straight pretty much and also crouching under some parts. Moving a piece of stone out of your way, run through the door.

The achievement should pop straight after the game has loaded. (After pressing any button at the loading screen)