4 - Processing Area, Incinerator Room Puzzle, Scorpion Key, Getting The Shotgun

When you're ready, head down the stairs near the Safe Room. The game becomes a little more difficult at this point. Proceed through the hall and you'll bump into a Molded creature around the corner. You have no choice but to take it down, which you should do with headshots. Shooting its limbs and body can slow it down but ultimately is a waste of bullets when headshots are faster. If the creature manages to attack you, press LB/L1 to block. The best strategy is: A clean headshot, back away, target the head again, clean headshot, repeat until the creature is dead.

Further down the hall, head into the door to your right to reach the Incineration Room. There's another Molded here, so take it out. The room contains some Gunpowder underneath the corpse lying on a medical bed. At the sink you can read a hint on the puzzle you now need to solve: Three a's and a handprint. This means 'Tamara' (the body bag door on the far right) and the one with the red handprint above it. This unlocks the one to the far left.

Reload your gun and inspect it to make a more powerful type of Molded drop out. Back away and shoot it in its head whenever you can, backtracking as far as the stairs if you must. When it's down head to the Incineration Room and check where it was lying to find the Dissection Room Key.

Continue and check the locked door to the left (stating 'Working Room'). Continue but ignore the door to the left, which does indeed lead to the Dissection Room, but you can't really go there, practically speaking, because the enemies beyond are quite tough and numerous. Let's get the shotgun first, shall we?

Open up the green divider and crouch. Check the left side of the wall next to the wooden pallet to find an Antiquated Coin.

Then smash the Two Boxes for items (one in the rack, one on the ground). Also grab the Processing Area Map. In the area with the sinks, check for the Treasure Photo, a Lockpick and the Scorpion Key.

There's also a Herb in a cage and a Chem Fluid in the metal cabinet near the door to the west. Head through the door, go downstairs and check the cart in the corner for Shotgun Shells x2. It's a dead-end for now since the Snake Door is locked, but you can find Psychostimulants and a Mr. Everywheres Statue on the left and lower right corners of the door respectively.

Go back upstairs and kill the Molded dropping from the ceiling as you move closer to the door you haven't went through yet. Defeat it and go through the door, leading back to the beginning of the area, and another Molder will appear. Kill it, then head back upstairs to the Safe Room where you can save your game and put your inventory partially in the storage. You can also use the newly found lockpick on the closed cabinet to find Handgun Ammunition x5.

Head through the corridor and a Molded can appear. If it does, head back to the Safe Room and it'll disappear most likely. You can then go through the corridor and use the Scorpion Key on the door to the right, leading to the Main Hall. Head upstairs and make your way to the Recreation Room. It's very likely that you'll encounter Jack in this area, somewhere. Take him out with headshots and generally keep your distance. Unfortunately he won't be downed for good, but only temporarily, so quickly be on your way.

In the Recreation Room, use the Scorpion Key and search the newly unlocked room for a Broken Shotgun, Handgun Ammunition x12 inside the cabinet, Chem Fluid, Shotgun Shells x2, and the files Memo About Relief and Doctor's Letter. You might also find some Burner Fuel x100 on the floor to the right of the desk. While Jack is still out cold, quickly head back to the Main Hall and collect the M37 Shotgun and replace it with the Broken Shotgun. Having done this you should pack enough firepower to continue in the basement.

There's one last optional thing to do now. Remember the photograph of the fireplace you found in the basement? This points to the room with the deer, also known as the Drawing Room, located not too far from the Safe Room at the top of the stairs leading to the basement. Inspect the fireplace carefully and a stone on the right will come loose, revealing the powerful Steroids item, which permanently increases your maximum health. Immediately consume it, then head back to the Safe Room.