Thieves Guild: Ahdarji's Hierloom
Your new doyen, S'krivva, lives in Bravil. Although she has a house near the North Gate, Christophe says not to bother her if the door is locked. Fairly good advice since S'krivva has a little side business as a skooma runner. But her door is open in the early morning every day and in the afternoon/evening every day except Tuesday and Thursday. On the whole, she's a lot more accessible than Christophe.
Once you have fenced more than 200 golds, S'krivva will have a mission for you. It seems that the guild really does take care of loyal members, even after death. Ahdarji, the widow of a guild fence, has had a ring stolen by a freelance thief. S'krivva would like you to talk to Ahdarji and see what you can do about getting it back for her. Since Ahdarji lives in Leyawiin, it's time to hit the road.
You can bribe the beggars in town to find out where she lives and what her schedule is. Talk to her to find that she wants you to retrieve the ring and kill the thief. If you politely point out that the Guild has rules against that sort of thing, she'll settle for your hurting him (a lot). The thief is none other than Amusei (this is why he couldn't win either of the "contests" - he was needed for some other quests). Besides being inept at finding quest targets, Amusei has managed to get himself thrown in jail. How such a complete goofball managed to break into Ahdarji's house and get her ring in the first place is a question best left for the sages. Since he's not going anywhere for a while, the only trick is going to be getting to him. Any guard with a disposition of 45 or better will be able to tell you that he's in the castle dungeons. But bribing up a beggar will get you the same information, as well as the fact that the jailor can be bribed into letting you visit a prisoner.
So into the castle dungeons you go. You don't actually have to bribe the jailor, although that's the quickest and easiest way of getting to Amusei. You can try to sneak past him and simply pick the lock if you wish. If you bribe him (it will cost you 20 gold), he'll go unlock the door for you. If you choose to save the gold and sneak, go down the stairs just before you get to the guard. Note the Evidence Chest in the back corner. If you have to get busted, Leyawiin is one of the more convenient places to retrieve your loot. The stairs up go back to the main passage on the other side of the guard. He does periodically patrol, so exercise caution. Pick the lock on the door around the corner (close it behind you so that you can Amusei can speak undistrubed) and you'll find Amusei in the last cell on the right.
Talk to Amusei, listen to his sob story about not being accepted by the Thieves Guild, and offer him a lockpick in exchange for his telling you what happened and where the ring is. It seems that the ring in question was stolen to begin with and no fence would touch it. So he tried to ransom it back to the Countess. She called the guards on him, took the ring, and Amusei got locked up for his trouble. So now the Countess has the ring. Don't worry about Amusei. He'll manage to pick the lock and sneak out of the castle in a few hours. Which again begs the question of how such an inept thief can manage a prison break that would give many PCs problems. If you'd like to be really nice to him, just pick the lock on his cell. He'll still want a lockpick, but it's a bit more realistic solution to my mind.
So, let's see if I've got this straight -- a thief stole the ring from the Countess and sold it to Ahdarji's husband, Ahdarji's husband gave it to her, Amusei stole it from Ahdarji, the guards stole it from Amusei and gave it back to the Countess (don't know if that actually qualifies as theft), and now you need to steal it back from the Countess and return it to Ahdarji. That ring should be collecting frequent-flyer miles. Although it's not necessary at this point, you can go talk to Ahdarji and let her know that Amusei tried to sell the ring back to the Countess. That conversation thread is available at any time until you actually return the ring to her and should be used eventually because it will cause her to double the reward for retrieving the ring (200 gold instead of 100). But there are better ways of doing things.
OK, so how to get to the Countess to retrieve the ring? Back to the beggars you go. They'll tell you that the Countess' maid, Hlidara Mothril, would know about the ring and also pass along rumors of a secret torture chamber somewhere in the castle. It would appear that Argonians are severly disliked in some quarters, but more importantly, there are secret passages that might prove to be useful. The maid eats dinner in the castle dining room at 8. She doesn't bribe easily, so a boosted Personality and Charm effects are recommended. You'll need her disposition up to 80 to get everything you need: the Countess goes to bed at 11 and puts the ring in her jewelry box, she's out of town from the 15th to the 17th of each month, and there are, indeed, secret passages that connect to the living quarters. You can go through all of this if you want or just head straight for the cellars (you're not reading this just for my sparkling prose and raucus wit, are you?).
The cellars are not a part of the castle that is open to the public, so exercise caution when entering. Down at the bottom, you'll find an open-topped barrel with a lever inside. Pull it to open the entrance to the secet passage. There shouldn't be anyone around until you get to the end of the secret passage, but stealth is still advised. There actually is a torture chamber, but to judge from the cobwebs it hasn't been used in quite a while, although the recent bloodstains would seem to indicate that it has. Your call on which is true. You can liberate stuff for fencing while you're down here, if you'd like. There should be a Silver Warhammer on the table and some leveled armor in the chest next to it and another chest hiding behind some chairs. You are a thief, after all. The passage will eventually end in a side chamber in the living quarters. While the Count and Countess are here, there is a patrolling guard and you'll need a very good Sneak skill to get by him. There is an alternative to this course, though. There is no guard when the Count and Countess are not there, so sneak in while they are away, pick the bedroom door lock and simply hide in the bedroom.
There is a very nice corner behind the desk, but you'll need a fair amount of Acrobatics to jump over the desk to get into it and a good Sneak skill to remain hidden there. Otherwise, use the dark corner near the bookcases (read "Warrior" for a skill boost), stealth and simply wait. Remember two things: you can't use the "Wait" function while you are tresspassing, so you'll just have to let the clock run. Also, your Sneaking is much better when you aren't moving (unless your skill is already over 75, which it probably isn't). If you've joined the Dark Brotherhood, you should have a set of armor and a hood that will boost your Sneak skill by 10 points (15 if you've reached the end of the questline) or any item with a Chameleon effect will also help. If you're going to use potions, bring a few because it will take a little bit of time before the both the Count and Countess to enter and go to bed.
Around 11, the Count and Countess will come to bed. Wait a few minutes, then pick the lock on the jewelry box, snag the ring and either sneak past the guard to get out or simply go back to hiding until the Count and Countess leave in the morning. Return the ring to Ahdarji to collect your gold (remember to tell her that Amusei tried to sell it back to the Countess before giving it to her). Then report back to S'krivva to get promoted to Prowler. As for Amusei, well, let's just say that we haven't seen the last of him yet.
Inside the Countess' jewelry box is a document called "Divining the Elder Scrolls" that is worth reading. It's not critical to any quests, but it does give a clue to what's coming: