"Elder knowledge" is a main quest mission. It has a tendency to glitch, but it can usually still be completed. In fact, I decided to write this guide, because the "Elder Knowledge" quest glitched on me.
If you believe the quest glitched on you or you're experiencing bugs, jump to the section of the guide titled, Glitches.
The following contains some spoilers.
Quest Giver: Paarthurnax
Locations: Alftand, Blackreach
Prerequisite Quest: The Throat of the World
Next Quest: Alduin's Bane
Concurrent Quest: Discerning the Transmundane
• (Optional) Talk to Esbern or (Optional) Talk to Arngeir
• Learn the location of the Elder Scroll
1. Receive the quest from Paarthurnax at The Throat of the World.
2. Talk to Esbern or Arngeir about the Elder Scroll.
3. Travel to the College of Winterhold, and talk to Urag gro-Shub. Select "I'm looking for an Elder Scroll." (See the Glitches section if this dialogue is unavailable.)
4. Travel to Septimus Signus's Outpost. Speak with Signus. Select "I heard you know about Elder Scrolls." (See the Glitches section if this dialogue is unavailable.) He'll give you the Attunement Sphere and a blank Lexicon.
5. Travel to Alftand and progress through the Alftand dungeon.
6. Enter Blackreach and make your way south, toward The Tower of Mzark.
7. Enter The Tower of Mzark and press the buttons in this order:
a. Second to right, four times until the Lexicon glows.
b. Second to left, twice until light illuminates from the Dwemer machine in the center.
c. Far left, once.
8. Grab the Elder Scroll and the Lexicon.
After completing "The Throat of the World" quest, Paarthurnax (The dragon on top of The Throat) will give you the "Elder Knowledge" quest.
He wants you to obtain an elder scroll to help combat Alduin, the dragon whose attempting to destroy the world.
Learning the Location of the Elder Scroll, Part 1:
Paarthurnax does not know the location of the elder scroll you seek, so you'll have to ask either Esbern or Arneir for help. Which character you choose to ask doesn't matter. They'll both point you in the direction of The College of Winterhold.
Joining The College of Winterhold:
If you've never been to the college before, travel to Winterhold. If you've already joined, you can skip to Learning the Location of the Elder Scroll, Part 2.
You can get to Winterhold via fast travel or you can use one of the horse and carriages that are located outside of each of the holds.
Once in Winterhold, proceed north towards the college. It's impossible to miss. As you pass through the gate, a mage named Faralda will ask you prove yourself worthy of the college. You can cast a spell, tell her you're the Dragonborn, or persuade her to let you in.
If you choose to cast a spell, she will randomly pick one of the following spells for you to cast:
• Casting a Firebolt at the eye-shaped seal next to her.
• Summoning a Flame Atronach on the seal.
• Casting Fear at the seal.
• Casting Healing Hands on her.
• Casting Magelight at the seal.
If you don't know the spell, she will sell it to you for a discounted price.
Telling her you're the dragonborn will also pique her interest. She'll ask you to prove yourself. Just shout and she'll let you proceed.
Or, if your speech is high enough you can persuade your way in the college.
Joining the College will start the quest "First Lessons". This is the beginning quest for the college.
Learning the Location of the Elder Scroll, Part 2:
Once inside the college, head north into Hall of the Elements. Once inside take a right and enter The Arcanaeum.
Talk to Urag gro-Shub (The orc behind the desk). Select "I'm looking for an Elder Scroll." (See the Glitches section if this dialogue is unavailable.) When he's done talking, he'll lay out two books for you, Effects of the Elder Scrolls and Ruminations on the Elder Scrolls. Read them and speak to him again, and he'll tell you to go to see Septimus Signus.
Exit the the college and travel your way around to the back, then head north until you reach a cave in the middle of an ice field. This is Septimus Signus's Outpost.
Once inside, speak with Signus. Select "I heard you know about Elder Scrolls." (See the Glitches section if this dialogue is unavailable.) Listen to him babble on for a while, and eventually, he'll give you two quest items: the Attunement Sphere, a key to the Dwemer ruins, and a blank Lexicon, needed to gain access to the Elder Scroll.
This dungeon is long and a bit difficult for low levels, so it's best if you prepare beforehand. You'll encounter Dwarven Spiders, Dwarven Spheres, Dwarven Centurions, Falmer, Chauruses, and some different weaker enemies.
Definitely save often. I'd recommend using multiple saves.
Go south-west of Winterhold to the Dwemer ruins, Alftand.
From the top of the Alftand ruins, on the left of one of the dilapidated cabins, is a walkway leading downward. Follow this walkway to Alftand Glacial Ruins.
Alftand Glacial Ruins:
After passing some wreakage, there's a little indented area with a treasure chest containing level-based loot. A little further on you'll hear two Khajiit arguing. Ignore them for now.
Be on the look out for Dwarven Spiders. They're the easiest of the Dwarven enemies, but be cautious, as some of them explode after death. They're often seen repairing broken equipment or clearing debris and sometimes appear from gold-colored pipes.
When you reach the room with the gate, don't bother attempting to open it. It can only be opened from the other side. In this room are some pipes, one of which contains a Dwarven Spider. Kill it and continue on ahead, but watch out for another pipe. It might house a Spider.
Soon you'll happen upon one of the Khajiit you heard earlier, standing over the other's corpse. He's hostile and seems to know of your presence even if you're sneaking. Kill him and look around the other Khajiit's corpse for a potion and a journal.
In the next room, you'll see a table with another journal. Walk around the wall and fight two Dwarven Spheres.
Dwarven Spheres hide in a round shell, but will pop out if provoked. They have much more health and deal more damage than Dwarven Spiders, but, just like the Spiders, they can appear out of holes in the wall. These look kinda' like the Hidey-holes from Bioshock.
After killing the Spheres, you can jump on the pistons in the back of the room to find a potion, some Dwarven ingot, and two chests.
Head to the next room and kill the two or three Dwarven Spiders there. Then, lockpick the gate for two chests.
Continue through the doorway and up the stairs. In front of the stairs is chest with a pressure plate in front of it, and to the right is a lone Spider and another chest.
Head left to fight two more Spiders. You notice an empty room and another room close of by a locked door. Behind the door is a chest with a Dwarven Sphere in front of it.
Follow the path until you exit out onto the second story of one of the previous sections. Avoid the pistons while making your way forward. At the end of each of row of pistons is a Spider.
Proceed into Alftand Animonculory.
Alftand Animonculory, Part 1:
After opening the first door you'll notice a gate with a gap in it. Enter through this to find a dead man, a chest, an arrow, a journal, and a lockpick.
Backtrack and kill the spider ahead. Walk up the stairs to fight one or two Spiders and a Sphere. Then you'll come to an incline. Move on while avoiding the pressure plates, open the gate, and trek down the long spiraling walkway.
If you have the Become Ethereal shout (The one that makes you invincible for a few seconds.), you can activate it, then jump all the way to the bottom, skipping a large section of the dungeon. If you do this, look out for the Falmer at the bottom. You don't have to fight them if you don't want, though.
Quickly get you're bearings, then run into the hallway, open the door, run ahead while avoiding the trap, and enter into Alftand Cathedral. Make sure to save before attempting this.
If you do this you can skip down to the Alftand Cathedral section of the solution. If not, continue with Alftand Animonculory, Part 2.
Alftand Animonculory, Part 2:
Near the beginning of this walkway, in a collapsed doorway on the left, is a lone Spider. Kill it and proceed ahead until you come between a door and a drop. Through the door is a Spider, a chest, and a locked gate containing a couple potions, a Dwarven helmet,and another chest. Jump off the drop to see a dead Orc with a potion and some arrows around her.
Up ahead is a walkway leading upward. At the end of this is a chest.
Continue further down and fight one or two of the Falmer.
The Falmer are a humanoid, elven race. They use both melee and marksmen weapons. They're blind, but have great hearing, so if you're sneaking, you'll need to move more carefully around them.
Move on ahead. Lookout for a tripwire or else you'll get hit by a claw-trap.
Soon, you'll see fire coming from a pipe above you and possibly another Falmer. Kill the Falmer, avoid the fire, enter the next room to fight two Falmer and proceed to the next area.
Here, you'll notice fire leaking from a couple pipes, some gas splashed all over the floor, and two or three Falmer. The leak won't ignite the gas, but you can ignite it yourself if you cast a flame spell on it.
Avoid the flames by either waiting for them to dissipate for a couple seconds or so and running past them, or you can cut around the back of the pipes, but be weary of the bone-chimes if you're sneaking, as they will alert the Falmer.
In the next room, below the two sets of stairs, are three or four Falmer. At the bottom of these stairs, and to the right is an elevator leading to early in the dungeon. You can use it, if you wish to retreat to grab some potions, sell some gear, or anything else.
On the other side of the wall is a table and some torture beds containing various alchemy ingredients, potions, weapons, and a few apparel items.
At the end of the room is another walkway going down. Below are three or four more Falmer and a Frostbite Spider. Kill the enemies, go down the walkway, and proceed through the hallway. Open the door, and make your way towards the next section of the dungeon, while be mindful of the obvious trap.
Move along the path to the right, avoid the pressure plates, and kill the Falmer.
Open the door, kill the two Falmer and the Chaurus.
The Chaurus is similar to the Frostbite Spider, but a bit more deadly.
You should see a gate in front of you. To right of it lead a path to a chest, and to the left are some stairs and a Falmer tent containing another chest.
Climb the stairs, to find third chest and a lever. Flip the lever to open the gate.
Past the gate, to the right is another chest. Up the stairs is the hardest enemy in the dungeon: the Dwarven Centurion.
Dwarven Centurions are the most powerful of the Dwemer. They're heavily armored, with a hammer on one arm and a spring-loaded spike on the other. They're slow, but vent superheated steam at a distance.
An easy way to defeat the Centurion is to trap him on the other side of the gate. Trigger him, then run back and close the gate. Now you can safely attack him with arrows and spells.
In the Centurion room, there's another gate. To the right of this is a chest.
Open the gate and enter the next room. In this room, there's two hostile NPCs arguing. If you'd like, you can sneak in, and let them bicker. Soon, they'll start fighting to the death. Kill the survivor.
In the back of this room is a locked gate. Inside it is another elevator. This one is a shortcut to Skyrim. You can leave and prepare for the rest of the dungeon if you need to.
At the center of this room is a Dwarven Mechanism that will activate some stairs around it. Use it, then go down the stairs, and open the door to Blackreach
I won't detail everything in Blackreach. It's a little too big for that, but I will explain the direction you should take.
There are a couple of different ways to reach the next section:
• Activate the large crossbow to kill the enemy in front of the building ahead. This will alert a Falmer way off to the left. You can crouch and wait for him to lose interest then sneak past him, or just kill him.
Jump down onto the path and head left, then within a few steps take the first right going west. On this path is a Dwarven Centurion, a Chaurus and two or three Falmer.
The path leads under a large structure with a Falmer on it. Continue along a little further until you reach a junction, and take the left.
To the left of this path there will be a couple Chauruses. Kill them and continue south down the path.
Soon you'll reach a bridge. At the end of this bridge, you should be able to see a tower in the distance. Follow the path to the tower, open the door, and use the lift.
• Activate the large crossbow to kill the enemy in front of the building ahead. Jump down unto the path and head right. You might be noticed by a Falmer. You can kill him or keep going.
Jump into the water and swim down the waterfall. Follow the water south and swim under the bridge.
Continue slightly west of south, while staying in the water. You might have to jump over some debris. Soon, you'll swim under another bridge way above you.
If you're going the right way you should see a tunnel to the right. After you swim under the third bridge. Follow the water west until you can climb onto the land to the right, then walk along the path. You should see a tower in the distance. When you arrive there, open the door, and use the lift.
Tower of Mzark:
Run forward into the next room, and take the path leading up. This device contains the Elder Scrolls. Run to the top and place the blank Lexicon in the Lexicon Receptacle. Then press the buttons in this order:
1. Second to right, four times until the Lexicon glows.
2. Second to left, twice until light illuminates from the Dwemer machine in the center.
3. Far left, once.
Finally, grab the the Elder Scroll in the center, to finish the quest and unlock your achievement. This will start the next quest, "Alduin's Bane".
Make sure to grab the Lexicon, so you can return it Septimus Signus later. Exit the door opposite of where you picked up the Elder Scroll and activate the lift. Then, pull the lever to open the gate.
• Esbern may not talk to you when you go to Sky Haven Temple. He just stands there and gives generic dialougue, forcing you to go to Arngeir.
• If Urag gro-Shub will not talk to you, there is a book on the desk, "The Rise and Fall of the Blades". Read it and then try talking to him.
• Sometimes when you talk to Urag gro-Shub, he won't give you the dialogue option "I'm looking for an Elder Scroll." If this happens, try selecting all the other dialogue options first. If that doesn't work, finishing the College of Winterhold quests will sometimes fix it.
Or, alternately, you can go straight to Septimus Signus's Outpost, north of the college, and talk to Septimus Signus.
• If you've already talked to Signus and accepted the "Discerning the Transmundane" quest before starting "Elder Knowledge", you won't be able to advance the quest objective, but you can still complete the quest by using the blank lexicon obtained from the "Discerning the Transmundane" quest. Read the Alftand section and the sections after it for a walkthrough on how to find the Elder Scroll.