Online:A Pearl of Great Price

Quick Walkthrough
#Talk to Ritemaster Iachesis.
#Retrieve the elixir.
#Observe the vision revealed by the Pearl.
#Travel to Rellenthil.
#Investigate the sinkhole with Valsirenn.
#Talk to Razum-dar.
#Report back to Ritemaster Iachesis.

Detailed Walkthrough
Starting the Quest
There are two ways you can start this quest.

If the quest is started through Ritemaster Iachesis right after The Queen's Decree:
:''"The next step involves a thorough examination of the strange pearl you and Valsirenn recovered from beneath the Shimmerene monastery. Hopefully, we can learn more about the false Aldarch and the source of the pearl's magic."
:You can use magic to get the pearl to reveal all that?
:"We are the Psijic Order, friend of Valsirenn. There is very little we cannot accomplish through the application of the Old Ways. Every object remembers its history. The trick involves selecting the correct ritual to reveal those buried memories."
:Can I do anything to help?
:"While I head inside to begin the augury ritual, I'd like you to go to Sotha Sil's study in the tower. Find my acolyte, Oriandra, and ask her for Sotha Sil's amplification elixir. We may need it if the pearl proves to be resistant to our magic."
:I'll find Oriandra and get the amplification elixir.

However, if you leave Artaeum then come back, you will have the opportunity to start the quest through Iradal:
:"Experimenting with time unfortunately leaves one rarely surprised. For example, I knew I would find you here."
:Do I know you?
:"I am a sage of the Psijic Order, as I assumed you would have realized since we're standing upon Artaeum. But I have a message. The Ritemaster requires your assistance. As I was going out anyway, I agreed to act as a messenger for you."
:"What does the Ritemaster need me to do?"
:"I'm sure the Ritemaster will provide details, though I can tell you it involved the augury spell he plans to cast upon the abyssal pearl that you and Valsirenn discovered. You can find the Ritemaster in Ceporah Tower, in the main gallery."
:I'll go and speak to the Ritemaster.'''

Enter the Ceporah Tower and see what Iachesis wants. You will find him in the center of the Tower's main lobby, channeling magic alongside several other Psijic sages. Speak with him.

Artaeum
Speaking with Ritemaster Iachesis
:''"Good, you're back. Valsirenn suggested you would be invaluable in our efforts to extract information from the abyssal pearl, and I concur. We've started the augury ritual, but the pearl has proven resistant to our efforts to reveal its secrets."
:You haven't been able to determine anything useful about the pearl?
:"A few insignificant echoes and a name to apply to it, but nothing to tell us who created it or what kind of magic it employs. It isn't Daedric in origin, though, despite the false Aldarch's allegiance. It's time to utilize more drastic means."
:What do you need me to do?
:"We're about to enter a crucial stage of the augury ritual, so none of us can leave this chamber. If you could find my acolyte, Oriandra, she'll provide you with the amplification elixir we require. She's in Sotha Sil's study, upstairs."
:I'll find Oriandra and get the amplification elixir.'''

The Ritual Components
Head west to Sotha Sil's study and talk to Oriandra.

:''"You must be the adventurer that Valsirenn was going on about. Allow me to be the first to welcome you to our secret island. Oh. I suppose you already talked to the Ritemaster, seeing as you're here in Ceporah Tower."
:The Ritemaster sent me to get an amplification elixir for the ritual they're conducting.
:"That strange pearl has certainly been reluctant to reveal its secrets. The Ritemaster hates it when an inanimate object refuses to cooperate. Regarding the amplification elixir, I just cataloged it. It's a Sotha Sil creation, as you'd expect."
:Sotha Sil's a member of the Psijic Order?
:"Hmm? What? No, not in the traditional sense. He's not one of our monks, if that's what you're asking. More like an honorary member, I guess you'd say. According to my records, the silver vial should be right over there."
:I'll find it.

Grab the   off of the table, and return to Iachesis.

:"Was Oriandra able to direct you to the proper elixir? Without something to amplify the magic, our ritual is going to fail."
:Here's the amplification elixir you requested.
:"Just in time! For the next stage of the ritual, if you have no objections, I'd like you to join us. Your experiences alongside Valsirenn might help reveal what has so far eluded our efforts."
:How can I help with the ritual?
:"We'll handle the magic. You pour the elixir into the scrying pool and stand close. As the ritual's power amplifies, your experiences with the pearl and the false Aldarch should help the augury do its job."
:And what is the augury's job exactly?
:"We want to discover the origin of the pearl and its strange magic. In addition, anything we can learn about the false Aldarch and his connection to the pearl would be helpful. Otherwise, we're stepping blindly into Oblivion's maw here."
:All right, tell me what you need me to do.
:"Pour the elixir into the pool. That should provide the final boost we need to trigger the augury."

The Augury Ritual
After you pour out the elixir, the pearl rises from the pool, and 3 blue silhouettes appear: the late Aldarch Tilcalar and two new faces.

:Aldarch Tilacar: "Here we stand, the most favored servants of Clavicus Vile, Mephala, and Nocturnal, on the verge of the greatest victory for our Princes!"
:Nocturnal's Earl: "Are you sure those creatures can be trusted?"
:Aldarch Tilacar: "Have no fear! Isn't that why we formed the Court of Bedlam? Besides, what happens next in Rellenthil will seal Summerset's fate!"

After witnessing the vision, speak to the Ritemaster again.
:"That … was unnerving. It seems the false Aldarch belonged to an alliance of Daedric cultists called the Court of Bedlam. Imagine, the faithful of Clavicus Vile, Mephala, and Nocturnal working together. This is more serious than I anticipated."
:Have you ever heard of the Court of Bedlam?
:"No, but I'm hardly an expert on the Daedric cults of Tamriel. The magic I sensed in the pearl, though. It doesn't contain the taint of Oblivion. We're missing something, but what? I suppose we'll need to find out what's going on in Rellenthil."
:I can travel to Rellenthil.
:"I hoped you'd say that. Rellenthil sits to the west of Shimmerene, just across the mountains. I'll send Valsirenn with you to talk to the Canonreeve. The false Aldarch may be dead, but Mephala's and Nocturnal's agents remain as well as the pearls."

Rellenthil
Arriving in Rellenthil
When you arrive at Rellenthil, Razum-dar will call out to you. Speak with Razum-dar and see what he has to say.

:"Raz's investigations have brought him to Rellenthil. When this one noticed your Psijic friend slip into town, Raz figured you'd be along soon. So, what did you discover on Artaeum, the island that isn't here anymore? Ow. That made Raz's head hurt!"
:We learned the false Aldarch belonged to a Daedric cult called the Court of Bedlam.
:"Yes, this one has been exploring the Daedric connection as well. But Raz hates Daedra. In Raz's experience, very little good comes from dealing with Daedra or their cultists. And this revelation brings you to Rellenthil, yes?"
:Other members of the cult mentioned that something was going to happen in Rellenthil.
:"That's disturbingly vague. Why must cryptic cultists be so ... cryptic? Well, Raz saw Valsirenn head toward Canonreeve Farmeldo's house. This one suggests we start our investigation of the area there."
:Right. That's where I was supposed to meet Valsirenn.'''

Head on down to Canonreeve Farmeldo's house. When you will arrive, you will be greeted by the sight of an argument.
:Canonreeve Farmeldo: ''"Go inside and we'll discuss this later. And take off that ridiculous hood!"'
:Nedoril: ''"Ridiculous? I'll show you what's ridiculous. I'll show you all!"

Canonreeve Farmeldo
After witnessing that little exchange, speak to the Canonreeve.
:"You'd think as Canonreeve I'd be immune to the troublesome temper of a spoiled and rebellious child. But what distinguished visitors I have today! A wandering sage, a well-dressed Khajiit, and you. What brings such a group to Rellenthil?"'
:'''We're investigating reports of unusual occurrences here in Rellenthil.
:"Investigating? For who? Well, there have been three reports this week of someone disappearing. And my intractable son Nedoril and his malcontent friends have been cavorting around the large sinkhole that recently appeared."
:Do you think the missing people, the sinkhole, and your son's friends are related?
:"What are you implying? They're just young and proud of their heritage. I wouldn't draw such a harsh conclusion without substantial evidence. I can't understand why they're fascinated with the sinkhole, but that doesn't make them criminals."
:Any objections to us investigating the sinkhole?
If your character is not an Altmer:
:"It's unusual for newcomers to encroach upon Altmer affairs, especially since we rarely saw any prior to the Queen's decree. If you want to investigate, I won't try to stop you. And if anything happens, maybe it will teach my son to avoid the place."
If your character is an Altmer:
:I suppose two High Elves and a well-dressed Khajiit can be trusted. Take a look around and let me know if you find anything significant. I just wish my son Nedoril would stay away from there. He's become so intense lately. A phase, I'm sure."
:I'll let you know if we find anything to be concerned about.

After speaking with Canonreeve, Razaum-dar will ask you to go an investigate.
:Razum-dar: "Raz wants to ask the Canonreeve a few more questions. Take the Psijic and go investigate the sinkhole."''

The Rellenthil Sinkhole
Head on over to the sinkhole with Valsirenn to investigate.

As you approach the Sinkhole, you'll see something very strange. There's a flash of bright light, and a knight in golden armor is yelling something. An Altmer woman who appeared to be picking flowers nearby reels back in surprise.
:Golden Knight:"Dawnbreaker, open the way!"
:Golden Knight:"Oh, come on! Stupid Daedric interference!"
:Golden Knight:''"I'll be ba—"''

The knight vanishes before he can finish. The civilian runs off up the path towards Russafeld, and you are left to ponder what just happened. All you can do now is continue towards the sinkhole.

Inside the Rellenthil Sinkhole
When you arrive inside the Sinkhole, there's already a commotion. An young High Elven woman comes running past you.
:Pennifen:''"Nedoril's mad!"
:Pennifen:"He attacked Eldhon! And one of those horrible creatures tore off my hood!"

Speak with Valsirenn about what you just heard.
:"That young woman was certainly in a hurry. And what was that about Nedoril and an attack?"
:She said that Nedoril attacked someone, and something about creatures.
:"Yes, well, let's be on our guard then. I don't think this sinkhole is completely natural. Its size concerns me. If the ground continues to fall away, it could swallow all of Rellenthil."
:Do you really think this sinkhole is that dangerous?
:"It certainly feels dangerous. And if it does figure into the Court of Bedlam's plans, well, I can't think of a more frightening event than watching Rellenthil get swallowed by a sinkhole. Let's proceed and find out what's going on down here."

Exploring the Sinkhole
Not too far in, Valsirenn will make a comment about the walls.
:Valsirenn: "The walls and ceiling. They don't look stable. I'll try to reinforce the weak spots and catch up with you."

Continue without her. As you make your way deeper into the sinkhole, you will be faced with various yaghra enemies.
:Valsirenn: "More of those yaghra creatures! Be careful."

Walk deeper into the caves. Valsirenn will look over through an opening in the rock, at a larger chamber.
:Valsirenn: "The size of this place! It's almost as if someone dug up through the island."
:"I'll teleport closer to the central area and meet you there."''

Midway through the caves, you hear someone's voice. They sound distressed.
:"Is someone there? Help! Please, help!"

Approaching the figure, you see that it's Eldhon, the person Pennifen said was stabbed earlier.
:"Crazy bastard ... stabbed me. Gods ... this hurts!"
:Tell me what happened.
:"It was just... kind of fun. Joining the ... Court of Bedlam. Espousing the virtues of our... Altmer heritage. But Nedoril... he took things too far..."
:What do you mean, too far?
:''"When we heard … that they planned to ... release those creatures ... I made the mistake ... of saying they were ... insane. Nedoril objected. Called me unworthy. That's when he stabbed me..."
:Eldhon, where's Nedoril now? Eldhon?

Eldhon dies, and Nedoril is seen in a section of the cave behind his corpse.
:Nedoril: "The Court of Bedlam will eradicate the lesser races!"
:Nedoril: "Maybe even deal with our unworthy Queen!"''

After Nedoril spews that compelling revelation, and runs off back into the caves. Continue onward and see if you can find where he's run off to. Eventually, you'll meet back up with Valsirenn. She motions towards a coral overhang.
:Valsirenn: "Over here! Keep quiet and tell me if you see what I see."

Look over the cliff. On the other side is a large grey creature... and Nedoril! Talk to Valsirenn.
:''"You see that, right? My eyes aren't playing tricks on me? That's a Sea Sload! They haven't been seen in Summerset since ... well, it's been centuries, at least!"
:What's a Sea Sload?
:"A vile and dangerous species. Very powerful. The Sea Sload come from the distant underwater kingdom of Ul'vor-Kus. Who's that hooded figure with the Sload? And look. More of those abyssal pearls. They're everywhere!"
:Why are the Sea Sload dangerous?
:"The Sload are a godless people, perhaps the most hated in Tamriel. And the Sea Sload are even worse! They employ depraved magic and have long coveted Summerset. They believe it once belonged to them. They pillage, release plagues. They're horrible!"
:Does this have something to do with the Court of Bedlam?
:"The hooded figure could be a member of this so-called Court of Bedlam. At this point, nothing would surprise me. That Sload has me worried, though. I can't think of anything worse than an alliance between those foul beasts and Daedric cultists."
:Could this be the source of the abyssal pearls?
:"They could certainly have a connection to the Sea Sload's submerged kingdom, but they appear to have been placed down here. Look how the yaghra are drawn to them. I'll head for the Sea Sload. You deal with those abyssal pearls!"

Nedoril will then warn his Sea Sload master:
:Nedoril: "Master, intruders in the cave!"
:K'Tora: "Heed me, my creatures! Destroy the intruders!"
:Valsirenn: "That young idiot! We need to get over there!"

Head down the path with Valsirenn, slaying yaghra as you go. 
:K'Tora: "Witness the power of K'Tora of the Abyssal Cabal!"
:Valsirenn: "Destroy the pearls! We can't let those creatures reach the surface."
:Valsirenn: "The Sea Sload and the hooded figure are gone. I'll try to determine where they disappeared to."

Destroy the Abyssal Pearls when you reach them. Once the pearls are destroyed, talk to Valsirenn.
:"Damn it, I wasn't fast enough!"
:So that's it? The Sea Sload escaped?
:"For the time being. Let's see what's through that opening."

Entering the next chamber, you will be greeted by the sight of a yaghra monstrosity.
:Valsirenn: "The Sea Sload left us something to remember it by. We need to dispatch that creature."''

After it is killed, leave the sinkhole. Once outside, you'll see Razum-dar, who prompts you to follow him: 
:Razum-dar: "Hurry, this way!"
:Razum-dar: ''"Somehow Raz knew he'd find you here!"
:Valsirenn: "Sea Sloads! This is worse than the Ritemaster imagined!"
:Valsirenn: "Meet me in Artaeum after you talk to the Queen's Eye."

Debriefing Razum-dar
After Valsirenn leaves, speak with Razum-dar and brief him on the situation.
:"Did the pretty Psijic say … Sea Sload? No, Raz must have heard wrong. That could not have been what she said."
:The Sea Sload K'Tora is working with the Court of Bedlam-including the Canonreeve's son.
:"Sload? That's bad. And Sea Sload? That sounds even worse! If the Sea Sload threaten Summerset, Queen Ayrenn must be informed. We need to act! Wait. What did you say about the Canonreeve's son?"
:Nedoril joined the Court of Bedlam. He killed a fellow initiate and was working with the Sload.
:"Daedra worshipers. In Summerset. And Sload! Raz likes this situation less and less. As for Nedoril, Raz knows how to deal with traitors. This one will meet you at the Canonreeve's house."
:I'll see you there.'''

The Queen's Justice
Once you arrive in the Canonreeve's house, you will overhear Farmeldo:
:Cannonreeve Farmeldo: "The Eye of the Queen! How dare you accuse my son of treason!"

Speak with the Canonreeve to explain what you witnessed.
:''"The Queen's Eye. How dare he not identify himself when he first arrived! And how dare he accuse my foolish son of something as serious as treason! The Queen shall hear of this, mark my words!"
:Nedoril's more than foolish. He killed a High Elf and is working with the Sea Sload.
:"Sea Sload? Plus all this nonsense about Altmer superiority? And now … murder? I am the Canonreeve of Rellenthil! I took an oath to serve and protect my community. How in the Queen's name am I supposed to reconcile my son's actions?"
:That's not something I can help you with.
:"Oh, Nedoril, what have you done? Please, you must talk to the Queen's Eye. He needs to show mercy. I'm sure we can find a way to resolve this without... oh, here comes Nedoril now."
:Your son has a lot to answer for, Canonreeve.

At this point, Nedoril comes down the stairs with some choice words for you.
:Nedoril: "I have a lot to answer for? The Court of Bedlam is going to turn me into a god!"
:Razum-dar: "Foolishness can be ignored. Murder and treason , not so much."
:Nedoril: "You and your Queen have no authority over a true Altmer, you mangy cat!"
:Razum-dar: "This one cannot allow your crimes to stand unanswered."''

Razum-dar proceeds to plunge his blade into Nedoril's chest, executing him on the spot.

:Canonreeve Farmeldo: "Nedoril! No… no. I understand. Rellenthil is loyal to the Queen."

After this, speak with Razum-dar.
:"Sometimes the Eye sees treason and must cut it out before it spreads. This one is sorry you had to witness that."
:'''Couldn't you have arrested Nedoril instead of executing him?
:"Blasphemy, treason, murder. How many crimes must one commit to attract the attention of the executioner's blade? Raz decided that a message had to be sent. Enemies of the Queen will not be tolerated."
:I've rarely seen you this serious.
:"Treason and the Queen's justice are serious business. Raz has been forced into this role on rare occasions, but he never seeks it out or looks forward to wielding the blade. A necessary part of my job, yes?"
:Is there anything else you need from me right now?
:"No. Raz will see to the Canonreeve and send word to the Queen before looking deeper into the Court of Bedlam. You should return to Artaeum and let the Psijics know what we learned. I tell you, five-claw, this whole situation makes Raz want to hiss."

Return to Artaeum
Now you must enter Ceporah Tower and speak with Ritemaster Iachesis about the happenings in Rellenthil, ending the quest.
:"Ah, friend of Valsirenn. I've been informed that you encountered a Sea Sload in a sinkhole beneath Rellenthil. That bodes ill for Summerset. Perhaps all of Nirn. I fear there are difficult days ahead."
:The Sea Sload called itself K'Tora. 
:"I'm familiar with that particular Sea Sload and its renegades. Call themselves the Abyssal Cabal. I thought I defeated them long ago, but it appears I was in error. What about the pearls? Valsirenn mentioned you encountered more in the sinkhole."
:K'Tora used abyssal pearls to summon yaghra to attack Rellenthil.
:"Val described those seaborne monstrosities. I have a vague recollection of K'Tora utilizing such creatures in the past, but for some reason the memories refuse to snap into focus. I suppose that's another mystery I'll need to look into."
:Why would the Daedric Princes require the aid of the Sea Sloads?
:"The Daedric Princes require minions to carry out their will, and the Sload have always had an interest in the green and pleasant island. It isn't hard to see why they might work together. For now, you have my thanks for assisting Valsirenn."''

Notes
The name of this quest is a reference to Matthew 13:46, the name of which was used for one of the four books of the Mormon faith: Pearl of Great Price.
 

Quest Stages