Amnesia: The Bunker

This is Story Related and cannot be missed.

If you are unsure how to do this after you turn the generator on for the first time you need to work to the officer quarters. There you will need to break into "Delisle" office and find his dogtag with a code on it. With this code in hand (codes are different every playthrough) head towards the mission storage and you will notice a red valve to turn to release the emergency lockdown.

This valve will break though and if you turn around you can jump up into the vent and get into the mission storage where you will find all of the soldiers lockers. Find the locker labeled "Delisle" put the code in grab the new valve go back outside put the new valve in the slot, turn it, and all the lockdown doors will lift and the achievement will unlock.

This is Story Related and cannot be missed.

If you are unsure how to do this after you turn the generator on for the first time you need to work to the officer quarters. There you will need to break into "Delisle" office and find his dogtag with a code on it. With this code in hand (codes are different every playthrough) head towards the mission storage and you will notice a red valve to turn to release the emergency lockdown.

This valve will break though and if you turn around you can jump up into the vent and get into the mission storage where you will find all of the soldiers lockers. Find the locker labeled "Delisle" put the code in grab the new valve go back outside put the new valve in the slot, turn it, and all the lockdown doors will lift and the achievement will unlock.