Season Unending

Despite warnings about a dragon, the Jarl of Whiterun says that he can't help with the effort to defeat it unless the civil war is stopped. Only the Greybeards are in a position to hold a peace council.

Objectives

 * Talk to Arngeir
 * Talk to General Tullius
 * Talk to Ulfric Stormcloak
 * Talk to Arngeir
 * Take your seat
 * Negotiate a truce

Walkthrough
The Dragonborn must talk to either Paarthurnax, Arngeir, or Esbern. Whoever is picked will say that they must talk to the Jarl of Whiterun to try and convince him to let them use Dragonsreach, which was originally designed to capture and house a dragon.

Jarl of Whiterun
The Dragonborn tries to enlist the aid of the Jarl Balgruuf; however, the Jarl will say that he cannot try to capture a dragon while Whiterun is under threat of attack. He says that if a peace treaty can be agreed between the Imperials and the Stormcloaks, he will help capture and hold a dragon. The Jarl will also suggest talking to the Greybeards, as both General Tullius and Ulfric Stormcloak highly respect them.

Note that if the Dragonborn has already completed the Civil War questline, thus ending Skyrim's civil war, then this quest will not need to be completed. Regardless of whether Whiterun is under the rule of Balgruuf the Greater or Vignar Gray-Mane, the Jarl will agree to capture Odahviing without talking to the Greybeards, and the main questline will be continued.

Getting the two sides to the table
The Dragonborn will speak to the Greybeards, who will agree to help negotiate a truce. Arngeir will suggest the Dragonborn speak to both General Tullius and Ulfric Stormcloak, and extend an invitation to meet with the Greybeards and discuss the future of Skyrim.

Note that if the Dragonborn has not yet chosen a side in the Civil War quest line, then upon speaking with both General Tullius and Ulfric the first time, there will be no dialogue option to tell either about the peace conference. Instead, after mentioning Helgen, each will assume that the Dragonborn wants to join their side. Each will direct them to their assistant (either Legate Rikke or Galmar Stone-Fist), and in most cases they will then end the conversation. Approaching each one a second time will now present the option to tell them about the Greybeards and the conference.

After speaking to both parties, returning to Arngeir and speaking with him will allow the conference to begin. However, Delphine and Esbern will show up demanding entrance to the conference representing the Blades. Arngeir initially refuses, but is ultimately persuaded to permit them to join.

Peace Treaty
Once the peace conference has started, the Dragonborn is given many options, mostly having to do with the side taken in Civil War questline.

Negotiation 1: Elenwen
As soon as the negotiations begin, Ulfric raises objections about Elenwen even being involved in this council, saying how the Thalmor should have nothing to do with Skyrim's politics. Tullius or Ulfric will ask what the Dragonborn's thoughts are:
 * 1) To agree with Tullius and keep Elenwen in the meeting.
 * 2) To agree with Ulfric and eject Elenwen from the meeting.

The choice made counts as 'a score' to the side the Dragonborn agrees with. If the disappointed side is not favoured in the next round, they may threaten to leave the negotiations, depending on the Dragonborn's stand in the civil war. They never will, but will at least say that they feel they are treated unfairly.

Negotiation 2: Markarth or Riften
The next item to discuss is giving up a major Hold.

If the Dragonborn has sided with the Stormcloaks, General Tullius will demand that Riften be turned over to the Empire. Otherwise (either if sided with the Imperials or no side yet selected), Ulfric will demand Markarth be surrendered to the Stormcloaks. The opposing faction’s reaction depends on the state of the Civil War: The faction that controls Markarth or Riften asks the Dragonborn what they believe is a fair trade for the city.

The answer is one of three choices:
 * 1) An exchange of a major Hold the opposition has.
 * 2) An exchange of a minor Hold the opposition has.
 * 3) Alternative dealing with choice in Civil War quest line (not available if no side has been chosen yet).

The council goes along with whatever choice is made. The side that controls Markarth or Riften will be unhappy if it is bargained for a minor Hold.

Negotiation 3/NA (Through Console Command): Minor Hold
If a console command is used to do the mission when the Stormcloaks or the Imperials only have their capital left, the other side will down size their demand to a minor hold. Here the Dragonborn has the choice of giving up a minor hold to the Imperials or the Stormcloaks. There is no difference in the speech other than at the end. If a minor hold is given up, Tullius tells the Dragonborn of his displeasure. He does not use that speech if it is kept. The Stormcloaks will take the deal either way.

Negotiation 4: Concessions
It is now time for the faction that has been favored less (and thus “losing” the negotiations) to ask for additional concessions. For each demand, the Dragonborn can choose whether to agree to the concession. If the Dragonborn continues to favour one side, the other will eventually say that they will, after all, act for the greater good, and they will agree to the terms in any case.

Conclusion
Once the treaty is agreed, the quest is complete. Arngeir summarises the terms of the agreement, including the new Jarls appointed due to Holds exchanged. If the Dragonborn has joined a side, and the agreement is beneficial or neutral for their side, their chief negotiator (Tullius or Ulfric) will compliment the Dragonborn's efforts and reward them with a levelled weapon.

After completing the peace treaty with both sides, the Civil War questline is halted until the main quest has been fully completed.

If the Dragonborn has sided with the Stormcloaks and has liberated Falkreath in the quest line Liberation of Skyrim, in which the next objective is to liberate the Reach, then it is possible that after completing Season Unending, the "Liberate the Reach" objective will also be complete. Note that the Liberation quest line cannot be completed if the Dragonborn has a bounty in either Windhelm or Solitude.

If the Dragonborn has sided with the Legion and decides to trade the Reach for the Rift, then the quest Compelling Tribute (Imperials) in the Civil War quest line is skipped.

Trivia

 * Whether Paarthurnax has been killed or not will affect the dialogue between Delphine, Esbern and Arngeir during the Blades' request to attend the negotiations.
 * Evgiir Unslaad, or Season Unending is the Ancient Nordic term for war. This is revealed through dialogue with Arngeir, which further reflects his opposition to war and his pessimism about the usefulness of the peace treaty.
 * It is implied that Ulfric Stormcloak already knew Delphine before the events of Season Unending. While listening to Esbern, he asks Delphine if Esbern is with her, referring to her by name. There is no dialogue during the quest to suggest that the two are meeting for the first time in High Hrothgar.
 * Dual casting Frenzy coupled with Quiet Casting on the council can create chaos, causing them to fight against each other. Despite this, neither side of the conflict will become hostile to the other or end the council.
 * Interestingly, despite both Delphine and Esbern being prime targets of the Thalmor, Elenwen will take no action nor demand that they be handed over by the Imperials.
 * In pure diplomatic terms, the best outcome of the negotiations that can be achieved is to gain one major and one minor Hold for trading one major Hold only. The "price" for this is to agree to the opposing party's request about Elenwen (e.g., sending her away if the Dragonborn sides with the Imperials). Although your chief negotiator will announce that the terms of the treaty clearly favour the other side, he will then silently admit that the Dragonborn has done well and grant an item reward.
 * When Arngeir announces the terms and conditions of the truce, he will say "step down" when referring to the original Jarls of the 2 affected Holds.
 * This quest is skipped if the Civil War questline has already been completed.

Bugs
Eine unendliche Geschichte Бесконечная пора