After reaching the upstairs room at Manfred Gayles House and interacting with the phonograph. You'll be tasked with burning some books in the fireplace. There are 4 books in total.
On the shelf to the left of the fireplace under a skull.
One of a unit to the immediate right.
One of a unit behind and to the left corner near a deer skull.
One on the large shelf to the right thats taking up an entire wall.
You'll know which books, as they're the only ones you can interact with and they cannot be dropped. Once collected, press
to place them in the fireplace one by one. The correct order is chosen for you.
Once you're done, a voice from the painting will speak. Now you need to find the candle and place in on the candle holder, and do this 3 times. The candles are easy to find and spawn one at a time. Once you've done this, your achievement will unlock and you'll get the key.