Incinerator Room puzzle solution
The first room in the Processing area contains the Dissection Room Key. This key is required to progress, but it is locked inside the far left incinerator chamber. To open it, look at the memo pinned above the sink for some clues. Open the chamber door with the bloody hand print in the center of the row, then open the chamber on the far right corner to unlock the left-most chamber with the Dissection Key. When you open the left chamber, a Moulder will come out and attack. If you are fast, you can grab the key off the gurney and run, slamming the door in the Moulder’s face. They cannot easily chase you — so you can either leave or kill it with a few bullets to the head.