The wraith screeched in agony. It thrashed wildly on the stone slab, lashing out with its claws as far as it could reach and trying desperately to shift its form into mist so it could flee. But it could not. Spectral chains constricted it and prevented it from shifting away as Thresh flayed layer after layer off of its form.

Dissipation for a wraith usually occurred when their forms received enough trauma that would have killed them in life or when exposed to sunlight or overwhelming magic, but Thresh had learned that there was a way to prevent it. The magic of the Isles responded most to those who were strong of will and there were few there who rival the willpower of the Warden. By ensnaring a soul and lashing his magic into them, he could simply will that they not dissipate, forcing them to remain as long as he wanted them to. It was a magic he had mastered over the centuries, practicing diligently to learn the limits wraith could take before dissipating despite his desires, and learning how to keep a soul in agony right before that point. Although these skills had been for simple amusement purposes, there were times, such as this, in which they proved useful for other means.

"Where is it," the Warden hissed, speaking more to himself rather than his victim, "I saw it on the girl. I know it has to be here, so where is it on you?"

A sound like shards of glass being dragged over each other was the wraith's response.

"Nothing."

Mist splayed upwards from the wraith's chest, hanging in the air like black threads around the wretched creature. There was a warped mimicry of a skeleton within the body with a harsh green light, the wraith's soul, pulsing wildly in the center of its chest, but there was no mark upon it; no inverted triangle that was so obvious on Achlys's soul.

"A pity."

Knowing he would gain no new information from this wraith, Thresh raised his scythe and brought it down in the center of the writhing thing's head. It dissipated at once.

"If only you had been the one," he spoke to the swirls of mist as he raised his lantern to them, "if only I could have found the mark on you, I could have tried to remove it. And if I were successful, you would have been freed."

The lantern closed with a click like rattling bones.

"How unfortunate that you were not."

There was a faint amount of sincerity in Thresh's voice as he spoke this final line. He felt no remorse for the damned soul, but for his own ambition, this was just another in a collection of mounting setbacks. Frustratingly enough, it appeared as though his earlier prediction about the mark, how it was singularly visible on Achlys since she was a living soul, still held true. This meant that no matter how many wraiths he tore apart (and he had flayed apart several since Achlys's meeting with Viego) he would get no further information about the mark that branded those of the Isles to Viego.

Now that the shrieks of the wraith were no longer filling the chamber, the Vaults seemed extraordinarily quiet. The stillness did not sit well with Thresh. He knew he had an eternity to solve this puzzle, but at the moment that fact was poor consolation. He needed something to distract himself for a bit.

With the way the tides were this time of the month, he knew that one of the outer islands was more likely to be visit by treasure hunters looking to scavenge a ship that had wrecked there last year. That thought at least was a pleasant one, so he began the twisting walk through the hallways of the Vaults towards the surface.

As he emerged from the Vaults, he became aware of the presence of another greater wraith and recognized it at once as Karthus. His soul had a distinct zealous aura about it, heated with self-proclaimed piety. It was a nauseating feeling to Thresh, unflinching devotion, for he had seen firsthand what it could do, both with rancid stagnation and passionate destruction.

He looked down the hill and could see the pale, baleful light the lich was giving off. He was making his way towards him, of that there was no doubt, but why?

"No, not 'why,' 'what.' What does he want from me?"

Karthus only approached him for two reasons; voice his disapproval of Thresh's treatment of souls, or make a demand regarding his daughter. But what could he need for Achlys? His precious little spark of light had managed to weather her king's fickle temperament. What more did he need and, more importantly, was this something Thresh could use to swing fortune back into his favor?

Deciding that it would do him no ill to learn what it was Karthus wanted, Thresh descended through the ruins to meet the other wraith. At the very least, this would prove to be a distraction from the frustration he was feeling earlier. He let the chains that hovered about him sway as they pleased as he walked. If he had chosen, he could move silently, but he usually preferred to make noise as he moved. He liked the panic it would cause to those who knew they were being hunted.

"Heading into the Vaults, Karthus," Thresh asked as he stepped before the lich, "I would be careful. Many of the cursed items affect the soul as well as the body."

"I have not come for anything in the Vaults, Thresh," Karthus responded.

"Oh, then why have you come? I do not see little Achlys with you, so this not for a lesson. Is there a new favor you are to ask of me?"

"No new favor, just an amendment to our previous arrangement."

"Oh?"

"Achlys's instruction."

"Are you dissatisfied with her growth?"

"No, far from it. Her magic is no longer killing her, it seems more powerful than ever before, and Viego has accepted her."

"Yes, aren't we all thrilled that happened?"

"I had no choice, Thresh. I would have kept her secret, but I would not risk her death. In the end though, it all turned out for the better. As it stands, there is only one thing I can think of that I would change about her current state of affairs."

"And that is?"

"The magic she is being taught."

"Well, you are her father. You can change what you are teaching her at any moment."

"It is not what I am teaching that is the concern. It is what you are teaching her."

"I am simply teaching her what she needs in order to survive. Also, we had agreed that you would not interfere with what I want to instruct her in."

"What we had agreed," Karthus repeated, "but that agreement was made under different circumstances, back when she had to be kept a secret. She no longer needs to remain a secret, but you Thresh, you still have something that needs to remain secret."

Anger struck Thresh like a nail driven through flesh; sudden, unwanted, and deeply unpleasant.

"Is that a threat, Karthus?" he asked, his voice as rigid and cold as ice.

"It is not," Karthus responded with an equally cool tone, "if you recall, I already told you that I intended to keep your treacherous thoughts a secret and I have no desire to reveal them to Viego."

"Then why bring them up?"

"Oh, I was just curious," Karthus said, a smug tone settling into his voice as he tried to mimic Thresh's cadence of speech, "I had said that derive no pleasure from watching others' distress, but I wanted to see if that was true, and though I am ashamed to admit it, I must confess that I did enjoy seeing your facade falter, if only slightly. Though it was only for a moment, you were concerned."

Thresh repressed the sudden and profound urge to dissipate Karthus then and there. The lich had not brought any members of his choir along, so clearly, he had not intended to fight, and even if he had, Thresh was confident that he would be victorious in a fight. He had centuries more experience than Karthus. But if he were to dissipate him, he knew it would create more annoyances than it would solve.

Since his introduction to Achlys, Viego had taken a renewed interest in the Deathsinger, and the sudden disappearance of him would risk having Viego search for answers and discovering what he had done. Far more likely though, Achlys would seek out her father and learn of his actions. If that were to happen, she would never trust him again and Thresh would lose out on his entertainment of watching Achlys use her magic to further his goals.

He stayed his hand.

"What is it about her instruction that you wish to change?" Thresh continued, keeping his emotions reined in, "I believe that what I have taught her has helped keep her alive."

"I do not doubt that, but I do not know everything you have taught her. You have deliberately kept some things secret from me. I despise that, but I tolerated it because there are things you are better suited to teach her than I am and you knew about Achlys were willing to keep her secret. That was what made you singularly unique as a teacher. She does not need to be a secret anymore, but she still need teachers. However, that teacher no longer needs to be you."

"Are you suggesting I am replicable?"

"I am."

Once again Thresh had to suppress the urge to dissipate Karthus.

"Hah!" he barked a laugh, "Replaceable am I? And what of the mark and my work to undo it? Are you no longer concerned of that?"

"Not as I once was. I know you still desire to study it though and I will allow you to if you remain her teacher. But as I had said, you will only remain her teacher if you agree to instruct her what I tell you to. Do you understand?"

Inwardly, Thresh balked at the idea of taking orders from Karthus, though outwardly his expression did not change. Achlys was too precious a resource to lose though, especially since he still had had no luck in finding the visible mark on any other wraith. And if he ever wanted to achieve his desire, he needed her.

"I understand," he said.

"I am glad to hear it," Karthus said, not without a little surprise in his voice.

"And what would you have me instruct her on? More of the same? Practice with levitation? Binding magic?"

"She does require practice in those areas, but I was also thinking it would be beneficial for her to learn how to ensnare and immobilize spirits. Were she to be attacked by something she could not bind to her will, I want her to be able to flee or incapacitate it while other wraiths fight on her behalf."

"A reasonable request. I can see that she learns some form of weakening magic."

Karthus was silent for a moment as he observed the other specter.

"You are being uncharacteristically agreeable?"

"Were you hoping I would struggle more?" Thresh asked with a harsh laugh, "Oh, Karthus, perhaps you do enjoy watching things struggle more than you would like to admit?"

The lich scowled at the thought.

"No," he denied sternly.

Thresh shrugged his shoulder.

"The truth," he answered, "is what it always has been. Achlys interests me. I want to continue playing a role in her growth and if that means that for a time, I must limit what I instruct her, so be it."

"You do little to inspire confidence," Karthus said, "but I will give you a chance to remain as her teacher. I will honor my word and our new arrangement."

"As will I."

Though he wanted nothing more than to wring the lich's throat with his chains, Thresh spoke the words of alliance. His mind however, was already puzzling on how best to continue pursuing his own ambition. He could wait, Thresh reminded himself. He had all eternity of time. And during that time, he would not forget this insult from Karthus, nor would he entirely cease trying to influence Achlys. He just needed another way to and fortunately for him, this other way was already quite dear to the girl and owed him a favor.