No One Escapes Cidhna Mine

After completing The Forsworn Conspiracy, the Markarth city guards frame the Dragonborn, starting this quest. You are locked in Cidhna Mine at one point deciding whether or not to free Madanach and become Forsworn. Depending on what you choose you can either receive the Armor of the Old Gods or the Silver-Blood Family Ring.

Quick Walkthrough

 * 1) Ask a prisoner about Madanach, then get past Borkul the Beast.
 * 2) Talk to Madanach.
 * 3) Speak to Braig and listen to his story.
 * 4) Return to Madanach.
 * 5) Options
 * Kill Madanach and leave Cidhna Mine through the secret escape path mentioned in Madanach's note.
 * Kill Grisvar the Unlucky and follow Madanach.

Walkthrough
After entering the mine and talking to Uraccen the Dragonborn learns that Madanach is located in a private cell which is being guarded by Borkul the Beast. After speaking to Borkul he tells the Dragonborn that he will only allow passage in exchange for a shiv as a toll. A prisoner named Grisvar the Unlucky will have a shiv, but he will only trade it for Skooma, which can be pickpocketed from Duach or Braig. Alternatively, Borkul can be challenged to a brawl, persuaded or given the Skooma directly. It is also possible to pickpocket the key to Madanach's cell from Borkul.

Note: Attacking Borkul outside of the brawl will cause all the prisoners to attack you, unless you are a strong mage character or a werewolf this is not recommended.

After gaining entrance to Madanach's cell, the player has four options:
 * Help Madanach. Madanach will try and convince the Dragonborn that he and his Forsworn are justified in their actions and sends the player to seek out the prisoner Braig and hear his story. After listening to Braig, return to Madanach and he will offer freedom, but he requires proof of loyalty. He requests the assassination of Grisvar the Unlucky, who has outlived his usefulness to the Forsworn Rebellion. After killing Grisvar, return to Madanach. Upon hearing news of the Grisvar's death, Madanach gathers the remaining prisoners and leads them to an escape tunnel that runs through the Markarth Ruins. At the end of the tunnel, the Dragonborn's belongings are returned to them by Kaie, and Madanach rewards the player with Armor of the Old Gods. Once outside, there is a confrontation between Thonar and Madanach. The Forsworn and Madanach charge the city, killing Thonar and all guards (and citizens) in sight. After they leave the city, they will continue running to Druadach Redoubt which will have several friendly Forsworn inside.
 * Kill Madanach (find a pickaxe) in his cell while in sneak so as not to be detected by the other guards and cell members, read the note on his body and use his escape route. Upon exiting, Thonar Silver-Blood greets the Dragonborn and rewards them with Silver-Blood Family Ring and your belongings. The ring is enchanted so that weapons and armor can be improved 15% better.
 * Kill everyone. After attacking a prisoner or Borkul, everyone (except Grisvar the Unlucky) becomes hostile. Thonar Silver-Blood will reward the Dragonborn with the Silver-Blood Family Ring. Essentially the same outcome as the second option. (Being a Werewolf is very useful in this method, as is a combination of the Elemental Fury Dragonshout with Berserker Rage.)
 * Alternatively, an option which allows the player to get both the Armor of the Old Gods and the Silver-Blood Family Ring, side with Madanach up until the Dragonborn is given the Armor of the Old Gods which is at the end of the Markarth Ruins, right before exiting to the city. After the dialogue and receiving the armor, attack Madanach, turning him hostile. Doing this while close to the door to Markarth will cause his followers to re-enter and attack the Dragonborn. After the player kills Madanach (and his followers), loot his body and read his note. Then exit out to Markarth and speak to Thonar. It is recommended that the player attack Madanach close to the door to Markarth because if not, his followers may not re-enter and it can be difficult to get the Silver-Blood Family Ring from Thonar as Madanach's followers will be waiting outside to attack. If done correctly, after killing Madanach and the rest of his Forsworn followers inside the Markarth Ruins, the player will exit out to a peaceful Markarth with Thonar waiting to speak with the Dragonborn and reward him/her with the Silver-Blood Family Ring and a pardon from the Jarl. Additionally, if the player speaks to Jarl Igmund afterwards, he will apologize for the wrongful imprisonment.
 * Once you have been rewarded (by either Madanach or Thonar Silver-Blood), all items that were confiscated from you upon entering Cidhna Mine will be returned to you.

Notable Loot
There are two main paths for escape, and each carries a reward:
 * Helping Madanach by killing Grisvar rewards the Armor of the Old Gods, a full set of enchanted Forsworn Armor (Light Armor).
 * Madanach's new headquarters at the Druadach Redoubt cave contains more valuable loot, free for the taking, and a map of all Forsworn encampments.
 * Killing Madanach and escaping alone rewards the Silver-Blood Family Ring, providing +15% Smithing.
 * If the player kills Madanach after receiving the Armor of the Old Gods and their belongings, but before leaving the Markarth Ruins, Thonar will greet him outside with the Silver-Blood Family Ring and the quest will be completed.
 * Once you have completed the quest, bear in mind that the body of Eltrys (remember him?) is still in the Shrine of Talos and can be looted for several hundred septims.

Trivia

 * If the player killed Madanach and is going through Markarth Ruins solo, a good way to beat the spiders and Dwarven machines is to run past the spiders until reaching the last room, where the Dwarven Spheres attack, then lead them back to the spiders to have them fight each other.
 * With a high Pickpocket skill, one can reverse-pickpocket Urzoga gra-Shugurz beforehand and smuggle equipment into the mine though you must be in reach to pickpocket her through the bars as the door instantly shuts as she begins walking.
 * Also, it's possible to shove Urzoga into the mine with you though for no apparent reason, whether to pickpocket her equipment or to simply kill her with the prisoners' help.
 * If you choose to kill Madanach, and you are a Nord, he will say "Come at me son of Skyrim!"
 * If you wish to complete the quest but avoid directly killing Grisvar, you can choose the 'Madanach says hello' dialogue option and wait. Grisvar will panic and start attacking, and the other prisoners attack and kill him.
 * If you choose to not side with any prisoner, you might have a hard time killing them all with just a pickaxe. But there is a trick to it. If you walk up on the hanging bridge and wait for them to stand directly in front of you, you can use the Unrelenting Force Dragon Shout. The prisoners will then fall off into the pit directly behind the bridge. The NPC's can't get out, but the player can, making it easy to pick them off one at a time.
 * At one point in the mission, the player is asked if they have any family, and can respond that they are outside Skyrim, that they are all dead, or that they don't have any that they care to talk about. This is perhaps the only time in the game where the Dragonborn can talk about their previous life.
 * When talking to Madanach for the first time, choosing the dialogue option 'How about revenge?' sometimes causes only him to attack. After killing him, the other prisoners will act normally.