Use your torch on the candle next to the boarded-up door. Examine the doll on the floor and the symbol on the wall just to the left of the candle. Turn around and walk over to the large desk. Light the candle on the desk with your torch. Read the note on the desk. Open the top left drawer and read another note inside. You need an object to unlock the top right drawer.
Head over to the painting on the far wall and pull it open to reveal a safe. Based on the note, try pressing each of the numbered buttons and pulling the handle to notice that numbers 3, 4 and 5 produce a different result. Enter combination 345 (any order will do) and pull the handle to find a key. Return to the desk and use the key on the top right drawer - you will end up with a mysterious box. Examine this in your inventory. You will find that you can open 6 triangular pieces at one end. Make sure the one with the separate symbol is open, and create the shape you saw on the wall earlier. When you have it correct, it will lock in place automatically. Go back to the symbol on the wall and use your completed box on it. After the bookcase moves to the side, go through the exit.
Go over to the small table and use your torch to light the candle, then read both notes. Return towards the base of the stairs, then across to a larger desk. Light the candle here, then read the book (mentioning the year 1861) and pick up the wooden wheel. Examine this in your inventory to see it has the numbers 0-9. Next head to the door beneath the stairs and read the note on it.
Return to the base of the stairs, then go upstairs. Head right first and look in the bookcase to find a dial with the numbers 10-19, as well as a note from First Librarian Mathius. Continue clockwise around the landing and pick up another wooden wheel, also showing the numbers 0-9. Light the candle on the wall here.
Continue clockwise and you will find yourself half way along the next landing. There is a lever here between 4 Kitsune masks. There is also another candle on the wall to light. Continue to the next corner. Look in the bookcase and read the book. Pick up the Olmec cube, and read the posters on the wall. Examine the Olmec cube and rotate the corners so you can see the four Olmec gods in the same orientation as on the right poster. You will find an Olmec key. Use this on the locked chest in the bookcase here. This will move the first Kitsune mask.
Proceed to the next corner. Here you will find 4 books in a bookcase, with a lever on each side. The levers allow you to change the positions of the 4 books. You need to rearrange the books in chronological order. The fastest way is to pull the left lever 3 times, then the right lever once. This will move the second Kitsune mask.
Go all the way around to the dial in the opposite bookcase. Attach your two wooden wheels to the top of this device. Set the bottom dial to 18, the top left dial to 6, and the top right dial to 1 (1861). This will move the third Kitsune mask.
Go to the final corner and pull the lever. This will move the fourth Kitsune mask. Go along to the middle of the landing between where the masks started and pull the lever.
Return downstairs and go through the door beneath the stairs.
Light the candle on the wall here and that there are 4 empty flasks and 2 valves. Go to the nearby small desk and light the candle on it. Read the note on the desk, and find a torn note in the top right drawer. Examine the torn note to see the numbers 773. There is a combination lock for the top left drawer, which you can open with combination 773. Inside you will find a strangely shaped piece of metal.
Cross the room towards a large stone well, then turn left and approach a small table. Read the letter here and pick up a vial. Light the high candle while you are here. Continue to the far side of the room. Light the candle here, then examine the Periodic Table of Elements on the wall. Use the strangely shaped metal on this to show the elements C, O, Cl and As. Also read the note on the desk here. Continue left to find several shelves filled with vials, and another candle to light. Use your empty vial on the Coal, Oxygen, Chlorine and Arsenic, and you will end up with all 4 in your inventory.
Go back to the apparatus from the beginning of the level. Pour your 4 ingredients into the 4 empty flasks. Turn the 2 valves, and you will end up with a corrosive agent in your vial. Go over to the well and use the corrosive agent on it, then climb down.
Look up to see a ladder you cannot reach. Head over towards the boxes and light the candle. Go through the corridor to the next area and light another candle, then cross over the water and head left. Examine the body to find an extendable cane, then read the letter. Return to the start with the ladder. Examine the cane in your inventory and press its end twice to extend it out and along - it will lock in place. Now use this on the ladder to retrieve it.
Go through to where you cross the water and attach the rusty ladder to the wall so you can climb up. If there is steam blocking your path, adjust the valves on the walls in the area to stop this, then go through. Turn another valve here, then go ahead and light a candle. Around to the left, search another body to find a key. Make sure you turn off this valve again. Return to the first area and adjust the valves so you can go up the ramp. Use the key in the door at the end.
Go over towards the desk and read the note on the barrels. Go to the dark area and through the door into a larger hall. Look at the note (with the numbers 0, 2, 9) and the strange abacus on the round tables to the left. Notice the large symbols carved into the wooden dance-floor. Go to the other accessible corner and pick up the mallet, then read another note. Examine the bookcase, and look at the 4 open books, which shows the symbols from the dance-floor. In order, these can be found in books with numbers in the bottom right corner of 2, 4 and 2.
Return to the abacus and drag 2 blocks to the right on the top row, 4 on the middle row, and 2 on the bottom row - when correct you will hear a click. Go around to the other side of the stairs and find a combination lock next to the door. Enter code 029. You will find a set of rectangular metal pieces.
Go to the table near the piano. Read the note, then use your metal pieces on the frame. Activate the music box on the piano, then use your mallet to hit the keys on the xylophone, matching the music from the music box. If they are numbered 1-8 from left to right, play notes 6, 3, 7, 1, 3. Now go up the stairs and through the door.
Ignore the flames ahead and go through the door to the left. Read the note on the low table and look at the triangle symbol on the wall. There is a matching triangle symbol above the portal in the wall, but it is facing the wrong way. Pull the lever next to the statue, and both the statue and the symbol above the mirror will rotate. Make sure the symbol is correctly aligned, then go through the portal.
In the room you reach, the symbol above the portal should be correctly aligned already. Go through the door, past the flames again and through the door opposite. Repeat the process with the next symbol and the hand statue so that it is correctly aligned, then go through the portal. Pull the lever in this room to align the symbol above the portal, then go back through it.
Assuming all 4 symbols are now correctly aligned, you will find yourself in a new room. Pick up the curved piece of metal leaning on the bed, and search the body on the bed to find another piece. Examine the shelves and pick up an ancient Egyptian scythe. Read the letter here. Turn around and use the scythe on the large jug, then search the broken pieces to find another piece of metal. There is a box on the table here that requires a combination.
Leave this room and go through the door opposite. Approach the table and pick up a fourth piece of metal. Attach the metal oval to the left part of the large ring, then the metal chunk to the bottom right, the curved metal to the top left, and the metal spiral to the bottom left. Read the note, which mentions the final piece. Go back to the previous room and approach the shelves again. Count the jars on each left shelf (4), middle shelf (2) and right shelf (5). Use the combination 425 to open the box on the table. Grab the large jewel from inside. Go to the other room again and insert the jewel into the metal sculpture.
Leave the room, turn right and go through the door at the end.
Go through the door into Patient 13's room. Light all the candles as you walk around this room. Go right and search the bookcase to find some rubbing supplies in a small box. Further around the room you will see an Alchemy poster on the wall, which indicates the 5 small pedestals near the middle of the room represent fire, water, air, earth and phosphorus.
There are 5 large round plaques on the wall with symbols and letters. Use your rubbing supplies on each of these plaques, and you will end up with 5 sketched sigils, each representing a different Lord of Hell. There are a series of books you can find around the room that will allow you to match the sigils of these Lords with the elements on the pedestals:. Using the other posters that list the Lords of Hell, the Lords on the plaques are:
- Bael: Fire
- Paimon: Water
- Asmoday: Air
- Belial: Earth
- Baphomet: Phosphorus
Walk around the room and place the correct sigil on each pedestal. The pentagram in the middle of the floor should turn completely red (if it is partially purple you will need to reposition the sigils). Go to the puzzle box in the corner of the room and enter CAMIO (one of the other Lords, and the only one that you can enter). Use the demon sigil that you receive on the middle of the pentagram.