Take the only direction you can go, toward some escalators to the right. Click again to go up, then again to approach the elevator door. Turn to the left and examine the card reader. Use the blue card from your inventory in the slot at the top right. Take two steps down the hallway; a security camera will spot you and you will be locked in. Go up the stairs. Turn right and go down the hall. Go into the corner with the green light above it. (So far you don't really have much choice as to which direction to go.) You will find yourself in a display room.
Turn to the right and examine the chest. You can place your inventory items in here if you choose to do so, but it's really not necessary at this point. These chests will be necessary later in the game. You only get a certain number of inventory slots, and if they are full, you will be unable to take new items, so you can store your current items in the chests and go back for them later. I will not discuss inventory management; chests are plentiful throughout the game, and it is easy to move from one location to another using the map feature in your inventory.
Examine the lion-shaped ewer to the left of the chest, then take it. It is automatically placed in your inventory; click the switch at the bottom right of your screen to "switch off" the inventory. This will trigger a cutscene that results in your being sent back in time to the reign of Charles V, in the year 1377.
1377
You find yourself in an empty room of the Louvre, the "Low room or Saint Louis' room" according to the map in your inventory, which room is empty but for a chest in the corner. If you look in the chest, you find all of your inventory items that you started the game with, except for the blue passcard. Take them and put them back in your inventory. In one of the corners of the room, diagonally from the chest, there is a hotspot on the wall near the top of the corner. Use your knife there to get some saltpeter.
Go to the arch with stairs and use it to enter another chamber, the "Large king's bedroom (counsel)." Take a step into the room in the direction you're facing, then turn back and use the diamond knife on the throne to reveal a parchment with some strange writing. Turn around to face the center of the room and take a step in that direction. Examine the window in the right wall. Use the diamond knife on it, then examine it again. In your inventory, combine the crossbow bolts with the crossbow, then use it on the guy standing outside. He dies and falls into the moat.
Go back and enter the door to the left of the throne. You find yourself in the "Large room." Go up the stairs to the balcony, cross to the other side, turn right, and examine the chandelier. You see a sleeping man down below. Use your knife on the rope that's on the left side of the screen. That oughta wake him up, er, make sure he never wakes up, I mean. Go back down the stairs and cross the room to where the guy is laying. Use him to wear his clothes. Take one step back into the room, then examine the hutch to the left of the door on the right. Take the jug of water. Back off from the closeup, then turn and look on the ground to the right of the door, near the edge of the long table, and take the bronze key. Exit through the door in front of you. Turn toward the left, then walk to the other side of the courtyard. Use the bronze key on the door. You will be in the "Cup-bearer's room."
Take a step into the room, turn toward the right, and take the bottle of alcohol from between two barrels. Take another step into the room, and examine the trunk to the left (the trunk on the right is an inventory management one). Use the crossbow/bolt on the trunk to open it. Take the saffron. Turn around and examine the window next to the barrels. Use your knife on the window, then look out to see the "Garden of the King and Queen." In your inventory, separate your crossbow from the bolts, then combine the crossbow with the rope and the hook. Use your crossbow/hook/rope combo on the gazebo. Enter the gazebo. Turn to the right and take one step into the corridor. Take the rose from the left wall. Continue down the corridor until you can examine an archway. A cutscene will occur. Exit the gazebo and return to the courtyard, either the way you came in or by using your map. Do not go down the other garden path (hmm, sounds like a proverb) or you will die.
Return to the courtyard, go past the well, and when you reach the far side, turn back and look at the well. Use the rope on the well. You find yourself in a room with an alchemist. After the cutscene, turn around and take the parchment from the lectern; it's a "magic formula for revelation." Examine the skull above the closed door to find a "small furniture key set with diamonds." Go through the closed door to find yourself in the moat. Walk around the moat until you can examine the dead guy; take the gold key that's laying next to him. Return to the alchemist's chamber and talk to him (use him) to learn the ingredients needed to clean the key. You already have the three ingredients: the rose, the saffron, and the alcohol; combine them in your inventory and then use the resulting blue paste on the still. Take the "Small key for manuscript clasp."
Return to the "Large king's bedroom" and use the "magic formula for revelation" on the parchment you found when you slit the throne. A recipe for deadly gas will be revealed. On the floor in front of the table near you is a skull in a case. Examine it, then use the flashlight on it. This will freak out the guy in the room and cause him to run away. Examine the trunk where the guy was standing, and take the "Aconite flower bottle." Cross the room to the fireplace. Turn around and use the jeweled key on the clasp at the end of the rail across the bench, then use the rail near its center to move it. Use the jug of water on the fireplace. Go into the fireplace and look up; by unlocking the rail you have opened the grate. Use your rope on the hotspot. You will find yourself in the "King's bedroom."
Take the stool to the left of the bed. Cross the room, open the wardrobe, and take the incense. There is a hotspot on the floor in front of the wardrobe; use the stool there and then climb up on the stool. Use your flashlight in the darkness to reveal the silver key. Take the key. Exit through the door to the left of the wardrobe. You will be in the "Library."
Step into the library, then the king will tell you to take the manuscript to the holy father. Turn around and pick up the manuscript from the bench. It is the "Encoded royal manuscript revealing the access to Pazuzu's hiding-place." Return to the king's bedroom, and you can hear the king leaving the library. Go back into the library. Now you can examine the red book on the stand in the middle of the room. Use the red key from the alchemist on the book. The book tells you which of the Zodiac panels (that are ringing the room near the ceiling) to push. Examine the set of three that's over the bookshelf to the left of the door. Push Capricorn (the goat-like one), Aquarius (the water-carrying one), then Pisces (the scaly one). A door will open under the one non-Zodiac symbol that's in the group of four. Take the tablet. In your inventory, combine the tablet with the encoded royal manuscript.
Return to the courtyard; stand outside the cup-bearer room. Turn to the right and look at the bridge between the second floor and the central tower. In your inventory, combine the crossbow, rope, and hook, then fire the hook at the bridge. Once you're up there, look at the encoded manuscript in your inventory and click on the eye icon to see it more clearly. Exit your inventory and look at the door. Push the buttons in the order they appear on the tablet/manuscript. The planets will align, and a keyhole will be revealed in the center. Use the silver key. You will find yourself in the "Dungeon: Royal treasury."
In your inventory, combine the ingredients for the poison gas: the Aconite flower bottle, the saltpeter, and the incense. Make sure you have the resulting red seeds and your gas mask in your inventory. Take a step into the room, then turn around to face the door you just came through. In the alcove to the left of the entrance is a chest. Examine it and use the gold key on the lock. Take the ruby from the scepter. In the second alcove to the left of the throne is a tapestry. Examine it, then use the ruby on the horse's head. Note the door across the alcove from the tapestry. This is a good time to save. Now go back into the center of the room and examine the throne. Take the Daemon from the left arm. This will trigger a timed sequence in which you have to quickly exit through the door across from the tapestry where you used the ruby: click once in the direction of that alcove, and then click on the door. You will go downstairs in the tower and be in the "Dungeon: guardroom."
Make sure you have your gas mask in your inventory. (If you have to go back to a chest and get it, you can use the map to jump back to this location.) Do not enter the room; instead turn around and use your red seeds on the coals, then quickly use your gas mask. That is the end of this segment of the game, and you will be prompted to insert CD 2.
1610
You find yourself back in the Low room. Go get your inventory items out of the trunk. Turn around and take a step into the room. At the base of one of the arches is an "Antimony tablet;" pick it up. Go under the arch; turn to the left and click on the window. You will find yourself in the courtyard. Turn right and look down near the wall and pick up the stone. Turn around and use the stone on the wagon to the right of the guard. Go into the corner near you and look up at the lit window. Click on it to overhear a conversation. Then use the dagger on the window and go in. You'll be in the Cup-bearers' room.
Step across the table and open the wardrobe. Take the clothes. Use your flashlight on the bottom of the wardrobe and take the "Sideboard key." Turn around and look under the table. Take the "Gun belonging to Mr de La Force's men." Take a step across the table again toward the little door. Close the top panel and take the "Key for service lift" that's revealed. Exit through the window.
In the courtyard, cross to stand in front of the lines of guards, then turn around and examine the barrels. Take the "Hemlock" that's lying there. Then enter the door between the lines of guards. You will be in the "Caryatid room." Turn to the right and make your way into the corner of the room to the corner. Look down to find the hotspot on the floor and use it. You will see a secret door opening. Look up at the balcony behind the armless statue. Use the crossbow/rope/hook there and climb up. Take the hammer and chisel that's laying there. Go through the secret door into the library.
Watch a cutscene with the alchemist. Slightly to the right of him is a "General purpose formula;" take it. Examine the table, then use the antimony tablet and the hemlock on it. Take the green sleeping potion.
Return to the Caryatid room. Go toward the fireplace. Turn left and use the guy to get a little speech about not disturbing the future Louis XIII. Approach the fireplace to witness another cutscene. Use the queen. She is very difficult to understand, but she apparently thinks you are Jacqueline (because you are wearing Jacqueline's clothes) and you never delivered a missive per her instructions; she tells you to go and look for it at once. Turn right, take a step, then turn left and use the Sideboard key on the paneled door to enter the "Ground floor service area." You can turn left and use the man to get a rude proposition and then go up the stairs, or you can just go up the stairs. You'll be in the "First floor service area."
Look at the dumbwaiter to the left and use the "Key for service lift" on the lower right corner. Use the lever inside and take the basket. This puts you in the "King's bedroom."
Approach the footman standing by the door and use the sleeping potion on him. Examine the king's bed and take the "Royal signet-ring." Go to the secretary and examine it. Open it, then from the top drawer on the right take the "Royal note revealing the entrance to a secret passage." From the middle drawer, take the "Holy water." To the left of the secretary is a table. Examine it. Open the shutters behind the table, pan to the right, and find the hotspot on a window. Use your crossbow/rope/hook to cross over. You'll end up in the "Kings portrait gallery."
Approach the fireplace. Take the "Fire tong" to the right of the fireplace. Open the chest to the left of the fireplace and take the log. Use the log on the fire. Turn around and look at the back of the throne. It says "Follow the path shown by the huntsmen and you will find the birth year of the greatest among them," a clue for later in the game.
Here is where the note from the king's bedroom comes into play. It says "From Louis take away Francois-hairy nose and Anne's Charles, then add the Francois with a feather." In the portrait gallery, one side has the kings and the other side has the queens, each queen across from her king. "Francois-hairy nose" is Francois I, the bearded one. Remember from the Caryatid room where the guy said the boy praying at the dead king's feet was to become King Louis XIII? That presumably means the kings were only up to Louis XII at the time the note was written, so "From Louis [XII] take away Francois [I] hairy nose ..." results in Louis XI. The Charles across from Anne de Bretagne is Charles VIII. The "Francois with the feather" is Francois II. This results in the order Louis XI, Francois I, Charles VIII, then Francois II. In this order, examine these four portraits and use the signet ring on the "H" at the base of the portraits. A secret door opens up under the queen's portrait at the end opposite the fireplace. Go down the stairs through the secret door. At the end, use the "General purpose formula" on the sealed door. Take one step into the "Ambassadors' room."
From where you stand, turn around and examine the plaque on the wall. It's in Latin. Facing that direction, take a step along the wall. Turn around and face the steps but don't go up; instead keep your cursor low and go underneath. Turn around to face the dark cloth and use your knife on the hotspot. Use the crossbow/bolt on the man that's revealed. He will die and fall out the window, then there is a cutscene where the evil priest offers to translate the Latin for you if you give him what he wants. He says it means, "When the dead demon looks at the red and powerful eagle, he will come back to life." Make sure you have your gas mask in your inventory, then examine the blue vase that the priest is facing, the one across from the big red eagle vase, and put the Daemon in the hole. Then you have to put on your gas mask quickly. The priest will die, then you will be approached by the young prince, who asks you to investigate the death of his father. Take the red eagle vase. It is the treasure "Aquila." But alas your daemon is lost. Climb up the scaffolding. Take one step, then find the hotspot on the ceiling with the picture of the bull. Use the hammer and chisel and take the "Bull shaped zodiacal key." Do not try this with any of the other Zodiac signs or you will die.
Go into the next room, the "Small ground floor gallery." Cross the room to the sleeping guard and take his "Lead gun bullets" and his "Powder flask." Combine the bullets with the gun and then the powder flask. You now have a loaded gun. Go back to the other end of the room and examine the door and tapestries. Click on each tapestry until it shows a reddish man with two dead birds on a pole (the huntsmen). When you have changed both tapestries, a number will be revealed, 1553, the king's birth year.
Return to the Caryatid room. Examine the dead king and use the fire tong on his scepter. Take the scepter from where it lays next to him.
Return to the Cup-bearers' room. Use the holy water on Jacqueline. She tells you she hid a missive somewhere in this room. Turn around and examine the recessed window to the left of the wardrobe. Take the "Royal books." Cross the room to the broken window where you came in, then turn around and face the thing on the wall to the right of the inventory chest. There will be a hotspot on the ground in front of the wall decoration; use the books there. Then climb the books and take the "Missive written with invisible ink." In your inventory, use the Revelation formula on the letter.
Return to the King's bedroom. Give the "Very incriminating missive!!" to the prince.
Return to the "Small ground floor gallery." On one of the benches along the wall is a picture of the clock mechanism. Find it and take it.
Return to the King's bedroom. Look at the clock. It has two square-shaped panels. Examine the upper panel. Set the time to 1:55 (I don't know if there was a clue for this; I got it by trial and error. One thing I note after the fact is that 1:55 is the first three digits of 1553.) and then use the scepter on the square hole at the bottom of the panel. Examine the lower panel. Use the bull-shaped key in the hole in the middle and set the numbers to 1553. Then turn the bull key until Aries appears. A secret door opens at the bottom of the clock. Take the Taurus figure.
Make sure you have your loaded gun in inventory, then return to the courtyard. A timed sequence ensues in which you have to get close to the barrels and shoot them. That's the end of this time period.
1770
This time the Low room appears unchanged from the last time segment. From the trunk select whatever inventory items you think you might need, or just the ones you think are real purty. Go into the darkened arch across the room and pick up the spool of copper wire. Exit out the window into the courtyard. The courtyard is quite different now. Cross the courtyard and go behind the central building until you see the woman standing in front of the lit-up wagon. Use her to exchange clothing. Take the "Well-lined purse," and take the cloth lying on the wagon. Take one step back the way you came, then turn around and examine the wall of the central building. There is a hotspot in the dark; use the crossbow/hook/rope on it. You are now inside the "Ruins of a freestone mansion." Talk to the gent seated at the table; it's the alchemist. Examine the wall to the left of the alchemist and take the "Magic formula revealing some of Anselme's basic secrets" from the desk. Open the desk drawer and take the "Pearl necklace."
Exit through the remains of the door just to the left of the desk. You will be in the central part of the building; in one of the far corners is a hotspot. Examine it, then take the "Zinc tile." Then turn around and look at the hole in what remains of the roof. Examine it, then use the crossbow/hook/rope on the spire. Then cross to the other far corner, the only direction you can go besides back the way you came. You will be back in the courtyard. Go back to where you exchanged clothes with the prostitute and pick up the "Copper ridgepole." Go back across the center and examine the figure sitting in front of the door. Give him your Well-lined purse, and he starts singing drunkenly; a distressed man stops him, which causes the door to stay open. You are back in the Caryatid room.
In one of the alcoves across from where you stand is a box of scrolls; take the "Score of ‘Bastien and Bastienne', Wolfgang Amadeus Mozart's first opera." Head left toward the Tribunal, then turn right and talk to the woman seated on the bench; it's the Marchioness whose favor the alchemist told you to curry. Go through the old service door into the Ground floor service area. Go through the double doors into "The Queen's guards room." Take the "Champagne glass" from the wine cooler across the room. In your inventory, combine the champagne glass with the necklace. Return to the Tribunal and give it to the Marchioness. Examine the table next to her and take the "Heart-shaped key."
Return to the Queen's guard room and use the heart-shaped key on the chest to the left of the fireplace. Take the dress from the drawer. Morgana will change clothes again. Turn around and use the Mozart score on the piano to trigger a conversation with the Marquis. Look at the bench to the left of the piano and take the "Key to the library."
Enter the door in the corner of the room, to the left of where you came in, and you will be in "Diane's room." Examine the cherub statue and use the "General purpose formula" on the grilled thing the cherub is holding. Take the "Flask full of acid" that's revealed. Turn around and take the "Generator crank handle" from the easel on which the painting stands.
Return to the service area and go up the stairs. In the corner is a little cabinet with some bottles on top. Examine the cabinet and use the acid on the locked door. Take the "Sulphate flask" from the row of bottles inside. Open the drawer and take the "Sheet of zinc" and the "Sheet of copper."
Enter the door to the "Science Academy." From the left bookshelf, take the "Memorandum on electricity." Use the key to the library on the bookshelf to the right and take the "Notes from a scientific expedition in Persia." In your inventory, combine the "Reveal" spell with the scientific expedition notes to learn how to recreate Pazuzu.
Examine the "Leyden jar," a device on the table against the wall. Use the generator crank handle on the leftmost part of the device. Take the "Leyden jar charged with electricity." Examine the table in the middle of the room.
Return to Diane's room and examine the double doors where you get a magnifying glass. Use the Leyden jar on the doorknobs, then enter through the door to "Apollo's gallery." Talk to the painter. Take one step into the gallery and take the "Step-ladder." Take another step into the gallery, then take a step toward the right corner to end up in the "Square room."
You can look at the paintings, but don't try to touch them or you will die. Cross the room toward the door on the left, then take another step toward the little table to the right of the door and take the "Exhibition catalogue from the Square Salon." Go back one step, then turn around and go down the stairs to the "Sculptor's workshop."
Take a step into the room, straight down the corridor, and take the "Bag of coal." Go back, turn around, and take a step into the open door. Talk to the sculptor. He says he will make the mold of the Daemon for you if you get a painting for him, the one of Christophe Allegrain. Look at the exhibition catalog's last page, number 18. The portrait he is talking about is by Mr. Duplessis, the painter you talked to in the Apollo's gallery. Return to Apollo's gallery and talk to the painter again. Return to the square room. Standing as close as you can get to the stairs, lay the Step-ladder on the floor, on the second hotspot to the right of the stairs. Take the top left painting, the "Portrait of Christophe Gabriel Allegrain." Here is what it looks like:
Return to the painter and use the painting on his easel (in the close-up). Take the painting back again after the painter adds the mallet and chisel. Return to the sculptor and give him the painting. Then give him the "Notes from a scientific expedition in Persia revealing a secret." He will make the mold and then leave the room. Take the "Pewter crockery" from the cabinet to the left of the exit. Take the "Sculpting mallet" from the shelf over the door. Use the bag of coal on the brick ovens, then use the Pewter crockery in the pans over the furnaces. Make sure you have the copper ridgepole and the gas mask in your inventory. When you go to lay the copper ridgepole in the pan with the pewter crockery, there will be a cutscene with the Marquis in which he demonstrates great interest in what you've learned. After the cutscene, use the copper ridgepole with the pewter crockery, which will trigger a timed sequence in which you have to put on your gas mask. The Marquis will be finished off. Use the sculpting mallet on the clay mold in which the Pazuzu was made and take the "Reconstruction of the Assyrian demon Pazuzu statuette."
Return to the Science Academy and examine the table in the middle of the room. Use the Sulphate flask in the empty vat. There are four wires hanging down into the two vats. From left to right, use the Pazuzu, the Zinc tile, the Sheet of zinc, and then the Sheet of copper. Then use the copper wire above the vats to connect all of the elements. Make sure you have the "General purpose formula" in your inventory. Save, then take the Pazuzu. When you exit your inventory, the sculptor will show his true colors and try to attack you. You must quickly use the "General purpose formula" on the fireplace. You will be prompted to insert CD 1.
Return to Modern Time
After the cutscene, you will find yourself in the Saint Louis room, which has been known as the Low room up until now. From the inventory chest, take the crossbow, the crossbow bolts, and the three magic formulas.
Go to the back of the room, under the arches, not the bright exit near the inventory chest. Use the crossbow/bolt on the cage door. Put the Leo artifact back on the pedestal that you originally got it from, the one right next to the inventory chest. Turn to the right of the bright exit and find another pedestal in the corner. Use the Taurus there. Cross the room to the arches. On the pedestal to the right, use the Aquila, and use the Daemon on the pedestal to the left. This will trigger a cutscene with three ghosts from the past coming back to tell you you screwed up big time by placing the four artifacts, the keys to the apocalypse, and they tell you to find the Black Templar's grave. You will be facing the fourth pedestal with your Daemon still in hand. Do not replace the Daemon on the pedestal; instead, quickly turn to the arches, go through, then examine the leftmost one against the back wall. Use the "Magic formula for revelation" on the floor, then use the "General purpose formula" on the door that's revealed, then take the "Magic fibula made by Anselme" from the skeleton's hand. In your inventory, combine the Magic fibula with the spell to reveal Anselme's secrets. This will cause you to be transported in time again.
Fourteenth Century/Endgame
Your Daemon is still in inventory, but you have no map. From the inventory chest, take your knife, crossbow, and crossbow bolts, and then in your inventory combine the crossbow/bolt.
There is one window that you can examine; do so and then use your knife on it. Look out and use your crossbow/bolt on the errant Templar.