The events leading to the Forsworn Conspiracy quest trigger the first time you enter Markarth. In the market, Margret is looking at a pendant and saying how it would look lovely on her sister. Weylin sneaks on her from behind, and shouts "The Reach belongs to the Forsworn!" as he stabs her in the back. As the city guards overcome him, he yells "I die for my people" as he collapses to the ground. There is lots of commotion about, and talk about the Forsworn. Hogni Red-Arm asks you if you saw that madman. A Forsworn agent, here in the city. A man named Eltrys approaches you, asking you if you are all right and saw what happened. Tell him you heard some shouting about the Forsworn. That was it. As he leaves, he tells you that you dropped some note to the ground and that it looks important. Ask him if it is his note. He will tell you that it must be yours, fell out of your pocket. In your Miscellaneous tab in the quest journal there should now be an objective to read Eltrys' note. Find it in your inventory under "Books". It says "Meet me at the Shrine of Talos."
Before leaving to meet with Eltrys, make sure to loot Margret's body for the Key to Margret's Room.
Note: If you were quick enough, and noticed Weylin attempting to murder Margret as you entered Markarth, and managed to kill him and prevent the murder, Margret will thank you for saving her life. She will give you a Silver Emerald necklace as a reward. Eltrys will still approach you with the note, and the quest will continue as normal.
Open your quest journal:
The Forsworn Conspiracy
I've received a note from a man named Eltrys in Markarth. He wants me to meet him at the Shrine of Talos, presumably to talk about the recent murder in Markarth's marketplace.
Objectives:
Go to the Shrine of Talos
The Shrine of Talos is to the Southwest of the market. Head there, and enter the shrine. Eltrys is standing near the statue. He tells you he is sorry for dragging you into Markarh's problems, but after that attack in the market, he is running out of time. You're an outsider and dangerous looking, so you'll do. Ask him what he is talking about. He will tell you everyone in the city wants answers. A man goes crazy in the market. Everyone knows he is a Forsworn agent. Guards do nothing. Nothing but clean up the mess. He wants you to find out why. This has been going on for years. All he has been able to do is find murder and blood. He needs help. He wants you to find out why that woman was attacked, who's behind Weylin and the Forsworn, and he will pay you for any information you bring him. Ask him what he knows about Margret. He tells you she is not from Markarth. The air about her screamed "outsider". Visitors to the city usually stay at the Silver Blood Inn. Ask him who Weylin was and where he lived. He will tell you that Weylin was one of the smelt workers. Eltrys used to have a job down there himself, casting silver ingots. He never knew much about Weylin, except he lives in the Warrens, like all other worker. If you ask Eltrys who are the Forsworn, he will tell you that they're remnants of the old rulers of Markarth. Natives of the Reach. Followers of the old ways. The Nords drove them out of the city. Ulfric Stormcloak and his men. That was about 20 years ago. But somehow they're still here, and they're killing people. Ask him if he has looked into those murders. He will tell you it all started when he was a boy. His father owned one of the mines. Rare for anyone who isn't a Nord. His father was killed. Guards said it was just a madman, but everyone knew the murderer was a member of the Forsworn. Eltrys has been trying to find out why ever since. Gotten nowhere so far, and then he got married and has child of his own. He was going to give up for his child's sake, but it's like his father ghost is haunting him asking him "Why?".
Your quest journal should now be updated:
Eltrys has asked me to uncover evidence surrounding the murder of woman in Markath's marketplace. who was attacked in broad daylight by a man claiming to be a member of the Forsworn.
Objectives:
Find evidence about Weylin
Find evidence about Margret
Margret Evidence
Head to the Silver-Blood Inn, just across the market. Talk to Kleppr, the innkeeper. Ask him if a woman named Margret stayed there. He will tell you that yes, she rented the nicest room they had for a whole month. You should now receive an optional objective to obtain the key to Margret's Room. You should have already looted the key from her body as instructed earlier, but if for some reason you did not, then now is your chance to obtain another key. Ask Kleppr if he has the key to her room. He will tell you he cannot hand it over due to privacy. If your speech skill is high, then try to PERSUADE or INTIMIDATE him into giving you the key. Otherwise, BRIBE him to get it. You could also go straight to her room and lockpick it (Adept lock)
Once you have obtained the key, go to her room to the Southeast and unlock the door. Search the End Table to find Margret's Journal. Read Margret's Journal. It will mention Thonar Silver-Blood, and you will now have a new objective in your quest journal, to find evidence about Thonar.
Weylin Evidence
Head to the Warrens, south of the market on the lower level. Talk to Mulush gro-Shugurz who is standing outside. Tell him you are looking into the market attack. Tell him you have questions about Weylin. He will tell you he doesn't care, he runs the Smelter and that's it. If your Speech skill is high you can try PERSUADING him or INTIMIDATING him to get more information, otherwise you should try BRIBING him. He will tell you about a piece of paper that was slipped to Weylin when he was paid last time. Your objective now is to get a key to Weylin's Room. Ask Mulush if he has the key to the room. He will tell you to go see Garvey for that.
Enter the Warrens and talk to Garvey. Tell him you need the key to Weylin's room. He will tell you that you don't belong here. You can PERSUADE him to give you the key by telling him it's important, BRIBE him with some gold, or INTIMIDATE him. After you have Weylin's key in your possession, go NE to his room. Steal from the chest to find Weylin's Note and read it. It says: "Weylin, you've been chosen to strike fear in the heart of the Nords. Go to the market tomorrow. You will know what to do. -N"
You will get a new objective to find out who this "N" is. Exit the Warrens, to be confronted by Dryston who will tell you that you have been digging around where you don't belong and he wants to teach you a lesson. Brawl with him. As you defeat him, he will reveal to you that N is Nepos the Nose. You will get a new objective to find evidence about Nepos.
Go to the Shrine of Talos to give an update to Eltrys. Tell him that Margret was investigating Thonar and that Weylin got his orders from Nepos. He will give you 600 gold for each piece of information.
Thonar Evidence
Leave the shrine and head to the Treasury House to investigate Thonar. Talk to Rhiada and tell her you need to see Thonar. She will tell you he asked not to be disturbed. Try to either persuade her that he is expecting you, or intimidate her, or bribe her. Then go NW and open the door. Speak to Thonar. Tell him you are there to talk about Margret. He will tell you she was an Imperial Agent, and to stay out of his business. Suddenly there is a commotion outside. Nana Ildene and Donnel (Thonar's servants) kill Rhiada and Betrid (Thonar's Wife) and then approach to kill you and Thonar. Defeat them. Thonar Silver-Blood is shaken. Ask him if he will talk now. He will tell you the Forsworn are his puppets, and that he has their "king" rotting in Cidhna Mine. The king was supposed to keep them under control. Ask him about the deal he made with the Forsworn and Madanach. Ask him also about the Cidhna mine and he tells you it's a secure prison in which he thought he could keep Madanach under control instead of executing him, but obviously his plan has backfired.
Nepos Evidence
Go to Nepo's house in the north part of the city on the top level. Uaile asks you what your business is in here. Tell her you are here to see Nepos. She tells you to come back some other time, but Nepos tells her to send you in. Tell him you know about Weylin. He will tell you that for 20 years he has been sending young ones to their deaths in the name of the Forsworn and he is tired of this. Ask him who is behind this and he will tell you that it is his king, Madanach. When the uprising fell at the hands of the Nords, they threw him in the mines. Nepos does not know how, but the king lives. Nepos gets Madanach's messages, and hands out his orders without questions.
You are attacked by Nepos' servants who are Forsworn agents. Defeat them, your mission is now to return to Eltrys. Head back to the Shrine of Talos. When you enter the Shrine, you see Eltrys' body near the statue, and guards surrounding him. They tell you they warned you to not interfere in their business, and that they will frame all recent murders on you. Ask them what they did to Eltrys. The will say that they did to him the same thing they did to anyone looking to change how things are around here. They had a nice deal going between Thonar and Madanach until you and Eltrys started snooping around. They tell you that since you wanted to find the man responsible for those killings, they will give you plenty of time with the King in Rags when you're in Cidhna mine. Tell them you will go quietly. They tell you that you will never see the sun again, no one escapes Cidhna mine.
"Eltrys is dead, and I've been framed for his murder. My only option to clear my name is to let myself be imprisoned inside Cidhna Mine and locate Madanach, the King in Rags"
You find youself now in the Cidhna Mine Prison. This completes the quest "The Forsworn Conspiracy" and starts the quest "No One Escapes Cidhna Mine"