Double Jeopardy [Quest]

Text of the Quest:

Evidence suggests that Vicereeve Pelidil and the Veiled Heritance are planning to attack the city of Woodhearth. To find Pelidils locatiuon, I must confront Asteril, the Thalmor Officer who was spying on Pelidils behalf. I need to speak to Oromin about accompanying me to the Thalmor Residence.

Treethane Fariel: From what you discovered, it's unquestionable at this point—the Veiled Heritance is planning something here, something even worse than killing the queen. I just hope it's not too late for us to stop them.
Hero: What do you think we should do now?
Treethane Fariel: There's something about Pelidil's orders ... the reference to Asteril seems strange, and Oromin still refuses to believe she betrayed us. Either way, Asteril's the key to unraveling this mess. We need to question her and find out what she knows.
Hero: Where do you think we can find her?
Treethane Fariel: Well, if she hasn't realized we're onto her, we might be able to catch her by surprise. She might be down at the Thalmor residence right now. I assume Oromin will want to be there when you confront her. The three of you should go quickly though.
Hero: We'll go right away.
Treethane Fariel: Even if Asteril's fled the city, you might be able to find some clues about Pelidil's plans in her quarters. Let's hope you find something, because otherwise we don't have much to go on.
Hero: What do you know about Vicereeve Pelidil?
Treethane Fariel: Not much really. I heard he just followed Prince Naemon around like a little lost puppy. Now he runs off with Naemon's body, steals the Staff of Magnus, and takes charge of the Veiled Heritance? It seems this puppy might have a bite after all.

Oromin: This is preposterous! Asteril has risked her life for the Dominion more times than I can count. She is one of my best officers. I refuse to believe this irresponsible slander until I have spoken with her myself.
Hero: Razum-dar and I both saw her in the Imperial tunnels.
Oromin: You must understand—one doesn't become a Thalmor agent until their loyalty is proven beyond question. If Asteril confesses or if we find substantial proof, I will admit I was wrong. Until then, I remain extremely skeptical.
Hero: Will you join us in confronting her?
Oromin: This is Thalmor business, and I am going to the Thalmor residence to confront Asteril myself. You are welcome to accompany me, if you choose.

Asteril: The corpse of an Altmer female lies cold upon the stone floor. She has clearly been dead for a considerable length of time.

Oromin: You see? It's clear that Asteril has been dead for some time, so she cannot have been the one you saw in the Imperial tunnels! I told you—say what you will about the Thalmor—but we do not have traitors in our midst.
Hero: You don't seem too bothered by her death.
Oromin: Her death troubles me greatly, but the integrity of the Thalmor is of greater concern, and I am pleased to be proven right in that respect. With that concern behind us, we can finally start searching for the true source of this treachery.
Hero: Who do you think killed her?
Oromin: Undoubtedly it was the same person that assumed her likeness and attempted to assassinate the queen ... er, Razum-dar. Speaking of the cat, it seems he may have found something.

Laryaril: 0h, perfect. My favorite people. The very faces of my failure ... and now you've tracked me down just to watch me die? You're just like my sister and the rest of the Thalmor. No sympathy whatsoever.
Hero: Where is Pelidil?
Laryaril: Heh. Funny you should ask. I was wondering the same thing. Then I realized he lured me here so his assassins could kill me. This is my reward for my loyal service. A blade in my gut and a nice, cold tomb.
Hero: Do you know what he's planning?
Laryaril: Planning? Oh, he's well past that point. As we speak, his armies are storming the shore up at Seaside Sanctuary. Once they've got a foothold there, they'll conquer all of Valenwood. And there's not a damn thing you can do about it.
Hero: The Veiled Heritance has armies?
Laryaril: Of course not. They're just one prong of the mighty trident with which Pelidil will smite the Dominion! He's signed a treaty with the Maormer. And with the Staff of Magnus he's going to raise an army of undead. Yes. Your days are numbered all right.
Hero: How did he make a deal with the Maormer?
Laryaril: It's simple enough. The Sea Elves have always coveted these shores. If they help Pelidil dismantle the Dominion, he's agreed to give them Valenwood. It's not like these damn Bosmer have done anything other than cause us trouble.
Hero: What about the rest of the Dominion?
Laryaril: You mean Elsweyr? Far as I know Pelidil doesn't even care. He just wants the Summerset Isles. I don't even think he wants to rule them himself ... as long as they're ruled by someone other than Naemon's sister.
Hero: Does he intend to raise Prince Naemon too?
Laryaril: Of course. Who better to lead an undead army than an undead prince? And if Pelidil brings him back, Naemon will be bound by the vicereeve's will. No longer will Pelidil need to worry about the prince making bad decisions.
Hero: Does Pelidil still think the prince can rule?
Laryaril: Ha! Pelidil says he's under no illusions about that fact, but he still gets rather glossy-eyed when speaking about Naemon. I suspect he still harbors some hope that the prince will play a role in the future he has envisioned.
Hero: Are you still loyal to Pelidil when he ordered you killed?
Laryaril: Ayrenn is a false queen and the Aldmeri Dominion is a pathetic joke. Nothing can change that fact, even Pelidil turning on me. I'll gladly sacrifice my life to bring about the Dominion's downfall. It means my life was worth something.
Hero: Was it worth murdering your own sister?
Laryaril: Having her as a twin was torture. While she climbed the ranks of the Thalmor, I was perceived as a failure. When Pelidil recruited me, it was my turn to shine. I have no regrets. Heh. In the end, Asteril and I both lost our lives for the cause.
Hero: There's nothing more for us to talk about.
Laryaril: Just leave me to die. I wouldn't accept your help and you'd be better off not offering.

Treethane Fariel: Razum-dar explained how we were fooled by Laryaril. I wish I had time to show proper gratitude, but he also told me that an army of Maormer, led by Vicereeve Pelidil, is making landing on our shores. Is this true?
Hero: That's what Laryaril said.
Treethane Fariel: Damn. Honestly, I rather hoped he misheard. I suppose that's rarely the case. Very well, then. I will muster the city's defenses, but there is only so much we can do. I'm certainly glad you're here. You and Razum-dar may be our best hope.
Hero: Complete Quest.