Unlikely Victory Achievement
Complete Chapter Four with the Plunger.
You can get the plunger by changing the wheel in the “little ink machine”. You do this by following the hint of the Haunted House that says “Turn Back”. Go back to the room of the Projectionist and open the crate that is now unlocked next to the power switch. Just take it and it will change in the final area, instead of the pipe, it will be a plunger.