The Horn of Jurgen Windcaller

Background
After demonstrating my abilities to learn the Words of Power and to Call Upon the Mighty Winds, the Greybeard Arngeir has sent me on a final trial - retrieving the Horn of Jurgen Windcaller from his tomb in Ustengrav, a burial in the marshes of Hjaalmarch.

Walkthrough
First, travel to Ustengrav, which is just northeast of Morthal. Inside are Mages, Necromancers, Draugr, and Conjurers fighting each other. A sneaky enough Dragonborn can let them handle each other and clean up the leftovers. There are four things of note in this tomb: a hard-to-reach room, a word of power for the Shout Become Ethereal, a puzzle room, and a note.

Ustengrav
The Horn of Jurgen Windcaller is easier to do on lower levels.

The Shout
The hard-to-reach room is in Ustengrav Depths. In there the large pillars have collapsed paths along them. Find the rock closest to the first pillar and jump across to it. Whirlwind Sprint is needed to reach the last two pillars. At the end, is a room with a dead Draugr, a Soul Gem, and a chest.

There is a waterfall in this cavern (the north side) and a path that leads down to it. A Word Wall for the Shout Become Ethereal. There is a level dependent draugr slumbering in a small cave behind the waterfall itself. There is also a chest there.

The puzzle room
There is a puzzle room with three stones that activate three timed doors, sprint to run through the stones and then quickly use Whirlwind Sprint to go through the gates. The stones are proximity sensitive, but only two of the three can be activated from one place, nor will a waiting follower keep them activated. Activate the two furthest from the gates. The third will activate and open its gate as it is passed using Whirlwind Sprint.

The flaming floor
After going through the catacomb-like room, there is a room with a large number of pressure-triggered fire traps on the floor. The curved diamond shapes in the center of each tile are different shades of gray. The lighter tiles are safe to step on, while the darker ones will trigger flame traps. Another solution, besides to use Whirlwind Sprint, is to use the Become Ethereal shout, which will render the flames harmless for as long as the shout is in effect. After passing the pressure plates, there may be one or two regular Frostbite Spiders and one Giant Frostbite Spider. It is also possible to walk on the rocky sides rather than the pressure tiles for most of the trapped hall. Another solution is to shoot the tiles with a spell such as Firebolt or Ice Spike. Flames/Sparks, etc. don't work. The impact of a bolt or spike is enough to set off the trap if it's not a safe tile.

The Unfortunate News
Unfortunately, the horn has been stolen and replaced with a note from Delphine. The note is in the stone hand at the place where the horn should be. The note must be actively taken and read, even though the quest system tells its contents when it announces that the Horn of Jurgen Windcaller quest failed.

The note sends the Dragonborn to the Sleeping Giant Inn in Riverwood. Talk to Delphine and ask for the attic room. She will say that they don't have an attic room, but to take the room on the left. Go into the room. If Delphine does not immediately enter the room, sleep or wait for a few hours. Delphine will then be there. After the conversation, follow her and she will give the Dovahkiin the horn. She will then ask that she be joined on a quest to be proved a Dragonborn. This begins the A Blade in the Dark quest.

Return to the Greybeards
Travel back to High Hrothgar and present the horn to Arngeir. The Greybeards will gather in the main hall where Wulfgar will teach the final word of the shout Unrelenting Force.

Following this the Greybeards will perform a ritual that formally recognizes the Dovahkiin a Dragonborn. The Greybeards shout at once in Dragon language the following:

"Long has the Storm Crown Languished with no worthy brow to sit upon. By our breath we bestow it now to you in the name of Kyne, in the name of Shor, and in the name of Atmora of old. You are Ysmir now, the Dragon of the North. Hearken to it."

Once the ritual is completed, the quest is completed.

Trivia

 * If the Dragonborn does not have any money when asking to rent the attic room from Delphine, the room can be rented for free.
 * After completing the quest, the Dragonborn can return to Ustengrav and activate the altar where the note was for a free Dragon Soul.
 * After presenting the horn to Arngeir, when he performs the ritual that formally recognizes the Dovahkiin as a Dragonborn, a follower that may be there will not die, even hearing the voices of the greybeards, knowing that even a whisper could kill anyone who is not prepared.

Bugs

 * If the Dragonborn skips entering the attic room and talks to Delphine outside, the Dragonborn will not receive the The Horn of Jurgen Windcaller and will not be able to continue on with the rest of the main storyline.
 * Solution: Enter this command in the console: setstage . Doing so will instantly complete the quest.
 * Xbox 360: there is a chance that the shout word Dah will be written on the floor and not be able to be learned.

Das Horn von Jurgen Windrufer Рог Юргена (Квест)