Note - this is a vanilla quest, though one that can be augmented by Bards College Expansion if the player chooses to accept the help of Helvana. This is documented here as the rest of the Bards College Expansion content is kicked off by completing this quest.
Speaking to Viarmo at the Bards College in Solitude will kick off the questline. This sends the player on a mission to retrieve King Olaf's Verse from Dead Men's Respite.
If Bards College Expansion is installed at the time, when the player leaves the College, they will be approached by Helvana. Helvana will offer to accompany them, if the player agrees, she will meet them by the entrance to the dungeon, and then will tag along inside.
Whether or not she joins the player will not change the quest objective, but will add some commentary and additional options inside of the dungeon if she does join.
The quest objective will lead the player to Dead Man's Respite.
Once inside the dungeon, a ghost will appear, beckon the player and then disappear through the locked gate ahead. The player will see a Ruby Dragonclaw sitting on a table in front of them. Taking this will open the first gate (as well as trigger some Draugr to attack).
Making their way through the dungeon, and following the objective marker, the player will eventually find a sealed door they can't get past, and will have to continue past it.
Eventually the player will end up in a room with some stairs in the middle of the room covered with a grate. A pullchain down one of the alcoves will open the grate and allow the player to reach a rock door. Activating the handle to the left of it will reveal the book "King Olaf's Verse" in the hand of a corpse, where the ghost from the start of the dungeon sits nearby. Upon looting the book, the ghost will disappear and the objective will update to return to the Bards College.
The only way out will be to backtrack through the dungeon.
When the player reaches the sealed door this time, the ghost will appear and open it for the player.
Inside, the player will face several rounds of Draugr, eventually fighting King Olaf. The player will find the key to exit on his corpse, and a Word Wall behind where his coffin lay.
If Helvana joined the player, after killing King Olaf she will take the key from him, and after watching the player receive the Word of Power, she will comment on what went on and hand the player the key - advising them to return to the college.
Once the player returns to Viarmo, he'll tell them the Verse is incomplete, and decide the correct course of action is to fill in the gaps himself. He'll ask the player for suggestions of how to fill in certain parts.
The player's choices at this point can only impact the gold reward at the end but otherwise don't change the outcome (successful Persuasion options during this part result in more gold later), so they can choose whichever options they like.
After choosing how the verse should play out, Viarmo will ask the player to meet him at the Blue Palace.
Once the player heads to the Blue Palace in Solitude and speaks to Viarmo, he'll proceed up to Elisif and read the verse that was constructed. Afterwards, Elisif will agree to reinstate the festival.
Viarmo will then send the player to speak to Jorn, another bard from the college in Solitude, to prepare the festival. Afterwards, the player will need to wait until night (past 8 pm) and return to the outside of the Bards College.
Upon arriving, Viarmo and many other bards will gather around the back of the courtyard area in front of the college. When the player approaches him, he'll burn the effigy of King Olaf, and declare the player a member of the college and the quest will complete.
At this point, if Bards College Expansion is installed, Helvana should approach immediately, and begin the next quest.
Otherwise, after installing Bards College Expansion, the next time the player approaches a settlement, Helvana will approach like a Courier to begin the next quest.