Thanks to all of you who took the time to review my story :)
Chapter betaed by the wonderful Miette!

Regulus apparated to Severus' home on his own while Severus flow-travelled with Jonathan. He had made sure to arrange the front porch of the house so it could not be seen by Muggles. He did not want to have to travel to some weird little back-alley before walking home each time.

"How do you apparate so smoothly?" asked Jonathan as they entered the house.

"Smoothly?" echoed Regulus. "I'm interested."

"I don't apparate. At least I don't think so," explained Severus. "This is called flow-travel, because you use magic flows to reach your destination."

"Magic flows?" repeated Regulus askance.

"The theory is that Magic exists around us under the form of flows, like little rivers moving all around us. Flow-traveling simply is moving along those flows."

"So it's different from apparating," said Jonathan thoughtfully.

"I'm not sure," answered Severus. "I don't know how to apparate."

Jonathan and Regulus looked at each other.

"We'll have to set up a test, teach you to apparate, then you can compare the two methods, and even teach us how to flow-travel," said Regulus decisively.

"Don't forget to invite Evan or he'll be jealous," added Jonathan.

"Evan and Lucius," agreed Severus. Once everything was solved.

"Nice home Severus," praised Jonathan as he observed the main room. "Unexpected but very relaxing, especially after tonight's meeting," he added with a grimace.

"True," agreed Regulus. "It feels the same as Prince Manor. Peaceful and quiet. Like your thoughts are entirely your own here."

Jonathan looked at him appraisingly.
"Did you feel it too tonight? I was angry and I did not know why. I tried to calm myself and it was like this anger was not my own but wanted to impose itself on me."

Regulus nodded.
"Tonight was not the first time I noticed something similar. It's not necessarily anger."

Severus chose his words carefully before intervening.
"Evan once wrote to me that bearing the Mark was wonderful as it made you part of the group, almost as if you were the same."

Jonathan looked at Severus thoughtfully.
"It's true. We got such a warm feeling of welcoming when we were first marked..."

"But now we influence each other. We always vote the same way," said Regulus softly.

Jonathan remained silent a moment before nodding slowly.
"It's true. We really are. Several times, once I was home, I wondered why I finally voted as I did... You think it's the Mark."

Jonathan looked at Severus steadily.

"Yes. Regulus and I both noticed it emits a wrongness similar to Dark Arts twisting. It is very faint right now, maybe one of the reasons you're feeling at peace. But the more numerous you are, the stronger the wrongness is."

He hesitated then added.
"From what I observe, you mimic Lord Voldemort's mood."

Visibly shaken, Jonathan looked at Severus sharply.
"Do you think he did it on purpose?"

Severus shook his head.
"I would need to study a Mark closely to be certain, but I think something went wrong in the casting."

"What are we waiting for?" asked Jonathan, pushing up his sleeve to reveal the Mark and handing his arm to Severus.

Regulus nodded as he did the same.

"Why don't we settle up better first?" suggested Severus, amazed at how easy it was, how trustful his friends were.

He gestured them toward the sofa as he used a locomotion spell to approach his own armchair closer to them and called for Dhaal. He needed his help in case he was wrong and Lord Voldemort had hidden a nasty spell in the Mark.
His Familiar appeared next to him, the size of a Saint-Bernard—smaller than the size he used when showing himself in Death Eaters meetings but bigger than his favoured size. He pushed himself tight against Severus' legs and Sensing Shields, warm presence in Severus' mind.

"I will guard you," Sensed Dhaal firmly.

Severus patted his head gently in thanks, Jonathan and Regulus watching them with interest, before turning his attention to his friends' exposed arms, the Marks ominous on their otherwise unblemished skin. Carefully, he gently Sensed around one Mark then the other, to get a feel for the various spells woven into it. He took great care to compare both Marks, any difference being significant. He found none. He did not Sense any ability to alert Lord Voldemort if the Marks were studied either. Instead, he Sensed the ability to convey to Lord Voldemort what the bearer of the Mark was feeling. He Sensed the ability to communicate short messages through the Mark. He Sensed the ability to call for a meeting and give away its location. He Sensed the ability to locate bearers of the Mark. He Sensed the ability to hide from non-bearers. He Sensed the faint threads linking all the Death Eaters together. He Sensed the other one, well hidden behind all other intents, which linked the Death Eaters to Lord Voldemort and fed him some of their Magic. He Sensed his twin link which fed the Lord's Magic to his followers. The link which was the source of the wrongness. The link with no defined intent yet which was trying to expand and absorb other internal magic flows, seeping in where it found a weakness. The link which had echoes who went away from the main thread and...
Dhaal suddenly called him back, using his Shields to cut Severus from the Marks. Severus blinked.

"I'm curious to know what you found out after one hour of immobile focus," said Regulus casually.

"First we should eat the collation your House-Elf brought Severus. You look a bit pale," countered Jonathan.

He felt light-headed. Do not give too much at once he reminded himself with irritation. Clearly he was not there yet when it came to Sensing. Dhaal Sensed his vehement agreement and scolded him for not practising enough since his return.

Tuei had put hot chocolate and brioche on the low table, as well as biscuits with chestnut cream. His friends brought the table close to Severus and they all helped themselves with the delicious snacks, Regulus and Jonathan idly discussing the latest Quidditch match.
After two cups, two helpings of brioche and several biscuits generously covered with chestnut cream, Severus felt more like himself and ready to lay out his findings.

"So. I've not found any ill-intent in the Mark, nor any intent to harm anyone studying the Mark. It seems to be a mix of spells, Dark ritual and blood Magic," explained Severus, quickly listing the various uses of the Mark he had determined. "The most important are the links which feed Magic to and from Lord Voldemort. I think he only wanted to take Magic from you but ended up giving some of his too. I'm not even certain he's aware of sharing his Magic with you."

"I don't understand," said Regulus angrily. "Absorbing foreign Magic is one of the surest ways to twist your core. Why would he do this? He cannot believe it will render him more powerful, several experiments have proven it was not the case."

"And what about us? Is he corrupting our core by giving us his Magic?" asked Jonathan alarmed.

"You know we instinctively reject foreign Magic, it's self-preservation," answered Severus. He hesitated then briefly Sensed Jonathan's and Regulus' cores over. "Yes, your core is not absorbing the foreign Magic. The corruption is centered on the Mark."

It might have been different during the meeting, but Severus was not going to suggest this to his friends just yet.

"That's a relief, though I really don't understand what Lord Voldemort is hoping to gain from this. So, you think the fact he takes Magic from us twists his core, so when he gives us Magic, it comes out twisted too," said Jonathan, thinking out loud. "But what of these echoes coming off from the link feeding us Lord Voldemort Magic?" he asked with obvious disgust. "Do they link us to other people than him?"

"No," answered Severus categorically. "It would not be in character with the man. And they really are echoes which feel like him."

"You know what they are," stated Regulus.

Severus nodded.
"I believe they are the cause of Lord Voldemort's Magic twisting. I believe they are the reason he's sharing his Magic with you without realising it. I believe they are the reason Lord Voldemort's Magic is trying to take you over and influence your feelings."

He forced himself to meet their gaze.
"I believe Lord Voldemort has created Horcruxes."

"Horcruxes," repeated Regulus numbly. "As in several?"

"Isn't one enough to prevent you from dying?" asked Jonathan perplexed.

"Yes, one Horcrux is enough to prevent your death if your body dies. However, one is easier to find and destroy than two. And three, well… You see the reasoning," answered Severus.

"But Horcruxes are dangerous. One of the darkest practices. Few outside the oldest Houses know how to create them, or even of the possibility of creating them. I have always been told to keep away from it, and if I ever find myself in a situation where I felt I had to create one, I was to limit myself to this only one and to reunite with it as quickly as feasible," said Regulus, pacing back and forth in the room.

"I was only told to destroy any Horcrux I came across," said Jonathan at a loss.

Severus hid a wince.
"I was rather thinking of reuniting them with Lord Voldemort. I hope it will cancel the twisting and thus give him his mind back."

"When do you think he created them?" asked Regulus frowning.

"I know he possessed at least one at the end of our fifth year," answered Severus, pointedly ignoring the obvious question of how he knew this. "I believe he created more after Abraxas' death."

"All this because he's afraid of dying?" asked Jonathan incredulously. "Do you think he takes Magic from us to replenish what he lost by creating Horcruxes?"

"It's not supposed to work like this," answered Regulus. "But I only have bare knowledge of Horcruxes," he added, looking at Severus.

"I honestly don't understand why he would do so," said Severus. "I knew about the Horcruxes when I came back, but not about him taking Magic from all of you. I need to think about it."

"You want to reunite Lord Voldemort with his Horcruxes," said Jonathan. "What is your plan?"

"I was hoping you would help me with it," said Severus sheepishly.

Regulus snorted.
"You don't ask for much."

They looked at each other, the weight of their knowledge hanging over them.

Jonathan sighed.
"You know I'm in."

Severus repressed a sigh of relief and smiled at his friend who smiled back tightly. Turning back toward Regulus, Severus waited in silence for the younger man's answer. He hoped he had not made a mistake.

Regulus took his time before finally speaking.
"Count me in. He's still our best chance for changes."

"Thank you."

"Alright," said Jonathan. "I need to go home or Mother will worry. When do we see each other next?"

"Soon," answered Regulus darkly.

Soon translated into one week later. They—Regulus, Jonathan and Severus but Severus' Grandfather as well—met in Severus' basement which he had converted into a thinking room, his lab in the attic sufficient for his current brewing needs.
The four of them had decided Severus' home was the best place to meet as it was outside wizard populated areas so they were less likely to be observed.
In the event Lord Voldemort used the Mark to look for them, he should not find it suspicious to have the four of them present with Severus as Augustus has taken on the role of a Mentor for Jonathan after his father's death. The older man had been Severus' Mentor's best friend so none would find it suspicious for Severus to reach out to him. Regulus was Jonathan and Severus' friend so his presence was legit too. Severus knew he would need to alternate their work meetings with some including Evan and Lucius as their continuous exclusion would raise eyebrows and hurt his friend and his Brother.
The ability of the Mark to convey what their bearers were feeling could become problematic but Severus believed that as long as they thought they were acting in the cause's best interest, they would not attract Lord Voldemort's attention. He wondered how the man dealt with the feelings of all the marked Death Eaters. Did he feel all their feelings at once? Could he choose to focus on one person specifically? Did these feelings affect him as well?
Both Kea and Dhaal had insisted on attending the meeting to protect them if needed. Kea had set up on Augustus' knees while Dhaal was perched on Severus' Grandfather's shoulder.

"We first need to define our objective clearly and list what we know," said Severus, gesturing at the big board beside him.

His three Horcruxes-solver partners nodded in agreement.

"Our objective is to reunite Lord Voldemort with his Horcruxes, right?" said Jonathan.

"Well, our prime objective is to implement Slytherin' rules in our world," replied Augustus. "We need Lord Voldemort to win the next elections to do so as there are no other candidates who could unite all our group, and we need him to apply Slytherin's rules when he's elected Minister of Magic. We have all noticed a change of behaviour in our leader these past years, which is getting more and more pronounced with a marked tendency toward paranoia and cruelty. It makes us doubt his ability to be Minister of Magic. Severus believes his behaviour changed because he created too many Horcruxes, thus twisting and corrupting his core. To heal him and hopefully get our Lord back as he was before, an ambitious, charismatic but objective leader, we need to reunite his core with his Horcruxes."

"Does he need to take back all his Horcruxes?" asked Regulus

"I thought you could never heal a twisted core," said Jonathan quietly.

"It is not so simple," answered Severus' Grandfather, turning to Jonathan to address the most pressing question. "To my knowledge, no Wizards who came to the point of twisting their core, no matter the cause of the twisting, managed to heal it by themselves. Several became truly evil tyrants who committed atrocities. They are the ones the Ministry uses as its reference on the matter as they are also the most famous ones. However, there are a few accounts of Wizards who managed to undo the twisting of their core with the help of others. Sadly, they do not explain how they did it."

"But why would you always need somebody else's help?" asked Jonathan, perplexed. "I thought you could heal a corrupted core if you stopped using the Dark Arts until it was healed."

"A corrupted core comes from always using external sacrifices instead of internal ones. The corruption begins because you have not truly paid Magic's price. Stopping to use the Dark Arts will only prevent the corruption from growing until your core is twisted," explained Severus. "And stopping from using the Dark Arts is extremely complicated when your core is altered. You know using the Dark Arts requires discipline and self-control. When your core is corrupted, you want to cast Dark Spells more and more even without necessity. It's even truer when your core is twisted. Of course, you're so used to using external sacrifices by that point that you're only increasing your debt to Magic. The more you cast Dark Spells, the more you owe Magic, the more your core is twisted, and the more you want to cast Dark spells."

"It becomes an addiction, like with alcohol," stated Regulus. "You keep on drinking even if it makes you miserable."

"Exactly," agreed Severus.

"Wait. You said the Horcruxes were the cause of Lord Voldemort's twisted core. So if we reunite him with his Horcruxes and convince him to pay all the sacrifices he owes Magic, he should be healed," said Jonathan.

"It may be more complicated than that. Paying back Magic is enough for a corrupted core, but for a twisted one… You may need to pay Magic back with interests," answered Severus.

"So you're saying Lord Voldemort will need to pay all the internal sacrifices he had refused to pay because it was too painful or too dangerous, as well as an unknown sacrifice that could be even worse and that we will need to determine," said Jonathan darkly.

"It's a work in progress. I would not have burdened you with this if I already had all the answers," replied Severus.

"From what Augustus and you said, we really need to reunite Lord Voldemort with all his Horcruxes," said Regulus sombrely, "but it won't be enough."

"Indeed," said Augustus with a wan smile. "I want to make sure the three of you are aware that reuniting Lord Voldemort with his Horcruxes may only be the beginning. I doubt he will suddenly change back only because we made him whole again. In fact, he will certainly see it as a betrayal at first."

"You sure know how to motivate troupes," drawled Severus, seeing Jonathan and Regulus defeated faces. "We can do this. It won't be easy but it's possible. We only need to find the right way to achieve our goal."

"Can I say I feel inadequate?" said Regulus in a teasing tone which belied the lost expression on his face.

"Don't worry, you're not alone to feel this way," joked Jonathan lamely.

"I promise I would not have asked you if I thought it was impossible," said Severus, feeling guilty as he realised his Apprenticeship had prepared him far better than his friends for this task.

"Do not feel so down younglings," said Augustus gently. "We have time to think, research, and improve. Nobody knows what we do. The situation could be far worse."

Severus smiled at his Grandfather gratefully as Jonathan and Regulus stood straighter after hearing the older man's words.

"Shall we plan now?" suggested Augustus, gesturing towards the empty board.

"Yes," answered Jonathan resolutely. "Let's plan."

One hour later, they had the rough outline of a plan.

Horcruxes:

1: Determine the number of Horcruxes
How: Severus through the Marks?
Risk of missing one?
Risk of a new one being created any day?
Is there a limit to the number of Horcruxes one can create?

2: Find the Horcruxes
How: Severus through the Marks? Regulus' House-Elf ? (how to remove the obliviate charm, are there memories to find back as they were not given away willingly?) Inquire if other weird occurrence with other Death Eaters which could be linked to Horcruxes? Inspire from the family monitoring devices?(see Enora Prewett's book watching over your family ?)

3: Retrieve the Horcruxes
How: Will Lord Voldemort know when we take them? What kind of protections to expect? Will the Horcruxes affect the ones who retrieve them? Can they try to become part of someone else's core (see unknown Egyptian diary, rumours of possession by Horcruxes)?
Is it dangerous to have all the Horcruxes regrouped together before the reunification? = learn and/or practice charms like Patronus, Protego Duo, Protego horribilis...
How to store them?

4: Unite Lord Voldemort with his Horcruxes
How: Possible to do it without him realising? Can it work if unconscious?
Potion?
Spell?
Runes?
Is there an order to respect? (order of creation or?)
Is there a particular place recommended for the reunification (or one to avoid?) like points of magical confluences or voids?

5: Make Lord Voldemort give back unpaid sacrifices to Magic without being identified. Determine if Magic requires more than the initial sacrifices' price.
How:?
Can it work if unconscious?
External source of Magic required to make the payment happen?
Possibility to evaluate what is the payment needed?
How to give payment without using the Dark Arts?

Dark Mark:
1) Find a way to prevent Lord Voldemort from influencing feelings and decisions through the Marks (even Evan and Lucius so it must be an object?)
2) How reunification may affect the Mark?

"Put like this, it will be easy as pie," said Regulus ironically.

Severus rolled his eyes at the younger man.
"You don't know how to make pie."

"Let's begin with the first step," said Jonathan resolutely as he ignored both of them. "I'm curious to know how many Horcruxes we are talking about. Can you try now Severus?"

Severus nodded.
"I don't see why not. However, I don't think I will be able to locate them."

Jonathan shrugged.
"I don't expect us to solve everything in one meeting, especially after writing down all we need to do," he said with a grimace.

Severus fetched the stone he had created for his Apprenticeship project to attenuate Magic flows. He hoped it would help him distinguish the echoes which had to be Horcruxes more easily.

"Jonathan, you're first," said Severus. "I will estimate a number through your Mark then we will compare to the number I find through Regulus'."

"Yes sir!" answered Jonathan smartly.

Severus glared at him.

"Evan is not here, I had to!" said Jonathan defensively.

"Sit," replied Severus.

They sat in front of each other, Jonathan holding his left arm to Severus. Severus took his arm in his left hand while his right held the stone and moved it around the Mark, trying to find the best place to put it to reveal the echoes he was looking for.

Lord Voldemort's Sense was easy to find, wrongness pouring from it. The echoes were faint, almost hidden behind it. Severus moved his stone slowly, trying to attenuate the Lord's Sense intensity. Gradually, it faded while the echoes' signal grew, until Severus could distinguish one, two, three, four of them. Four Horcruxes. Severus swallowed thickly. No wonder the Lord's core was corrupted. Four of his seven Khorlos were split apart, had been for several years.
Shaking his head to himself, he gestured for Regulus to take Jonathan's place and repeated the process. He took his time, making sure he had not missed one echo because he had found four with Jonathan. When he was convinced there were only—more than enough—four echoes, he released his focus and promptly felt light-headed.

His Grandfather had apparently anticipated the situation as the older man made Severus relax against the back of his armchair and pressed a mug of hot chocolate to his lips. Severus avidly drank half of the cup before pausing, feeling his dizziness disappear.

"Eat Severus," said Jonathan with a frown. "This certainly takes a lot out of you. Tuei was kind enough to provide chocolate cake and French toast."

Severus did not protest and ate what his friend put on his plate.

"This certainly was impressive Severus," commented Augustus. "I consider myself proficient enough with Magic subtleties but I must admit that even following you with Dhaal's help, I did not sense any echo, though Lord Voldemort's corruption was suffocating. I do not know how you can bear to be aware of it all the time."

"I did not Sense your presence," said Severus intrigued.

"From what Dhaal was able to convey to me, which is not much, it is because he overshadowed my presence with his as not to distract you."

Severus raised an eyebrow at his Familiar who Sensed back a sheepish apology with an added feeling of I-was-not-sure-I-could-until-I-tried.

"Would you teach me Severus?" asked Regulus eagerly.

Severus looked at him thoughtfully.

"Ask me again when you finish your Apprenticeship," he finally answered.

He needed to clear with himself what he was willing to teach from his goblin knowledge. He also needed some time to find out if some part of this knowledge was known somewhere else in the Wizarding world.

"I will," answered Regulus with a glint in his eyes telling Severus without a doubt that the younger man would not forget this conversation.

They held each other's gaze until Augustus broke the silent contest.

"How many?"

"Four."

Augustus sighed. Regulus looked horrified. Jonathan did not seem to grasp the importance of the number.

"How many can you create? I mean, Horcruxes are supposed to be part of your soul. If they only are a tiny bit of it, you could theoretically create an infinity of them, right?" asked Jonathan.

"It does not work this way from what I learnt," answered Severus. "You know we recognise different kinds of Magic, you can create air elementals, earth elementals... In total, seven kinds of Magic exist, which is why seven is a number so often used in Rituals," explained Severus, visualising the Khorlos map he had learnt during his Apprenticeship.

"First, you have the most well known, earth, water, fire and air. Then it becomes less concrete. You have what is called ether which represents our ability to communicate with each other. Then you have the spirit, or our ability to think and understand. Finally, you have what is called vibration. I believe the name is imperfect because we do not really understand all it encompasses. Ghosts, Faes and some other magical creatures exist both on our plane and on another that is also magical but different from ours. Vibration represents this second plane. In theory, your soul is composed of these seven kinds of Magic. When you create a Horcrux, you cut in two one kind of Magic: one part remains with your soul, the other becomes the Horcrux."

"Can you choose which part of your soul you wish to cut? Do you think Lord Voldemort finally cut into his spirit part and it's what twisted his core?" asked Jonathan, fascinated.

"I suppose it's possible but I honestly don't know," answered Severus, both intrigued and repulsed by the possibilities Jonathan suggested.

"I think his core is twisted because more than one quarter of it is missing," said Regulus coldly.

Severus wondered if he was rethinking the need to help Lord Voldemort instead of simply destroying the Horcruxes.

"Well boys. I think this is enough for today. Severus needs to rest and we must all think about what we now know. We will meet again next week," said Augustus, getting up to emphasise his words.

Regulus and Jonathan imitated him reluctantly.

"Do you think we should bring someone else to help?" asked Jonathan hesitantly. "Someone with more experience or…"

Augustus shook his head with a compassionate smile.
"I understand why you would wish to Jonathan. The three of you are still so young... But we do not know who else we can trust. You realise that anyone learning about the existence of the Horcruxes is a danger to our cause. Imagine how Minister Birkins or Dumbledore could use this information to turn on our Lord as well as all his followers. They would brand us all Dark Lords. Ironically, the four of us might be even more at risk if some of our most fervent members discovered the Horcruxes' existence and our plan to reunite them with Lord Voldemort. We would become traitors and I don't wish to discover what our punishment would be."

Jonathan nodded in silence, face resolute.

Once more, Severus wondered if he should have kept his knowledge to himself. He had been selfish to share this burden with his friends. But he did not think he could manage on his own.

They left Severus with strong orders to rest and listen to Tuei, the House Elf assuring them he would do nothing strenuous today or else.

Five days later, they met back at Severus' for the next phase. Once they were comfortably settled in the thinking room, they focused on elaborating their strategy to find the four Horcruxes.

"I think we can rule out the possibility of them being kept together. It would completely defeat their purpose," began Augustus.

"Yes, I think we all agree no Slytherin would keep all his eggs in the same basket," concurred Regulus. "Severus, I was wondering if you could use your way of apparating to find them?"

"Flow-travel?" asked Severus.

"Yes. From what you told us, you follow magic flows to move yourself. You could follow the echoes to their source," explained Regulus.

"I'm not sure it would be safe," said Jonathan. "The Horcruxes have to be protected. Knowing Lord Voldemort, the protections will be complex and unusual. Plus we do not know how the Horcruxes will react to our presence."

"I agree," nodded Severus. "And I'm not sure I could both follow an echo and bring someone else with me."

"And I remind you we must be at least two to go examine a Horcrux location," said Augustus sternly, looking at each of them in turn.

They all nodded. Horcruxes were dangerous even without the added protections Lord Voldemort was bound to have added. There was no need to play the Gryffindors and rush in alone in hope of getting all the glory.

"Which reminds me," continued Augustus, "I did extensive research in the Prince library and I found indications that Horcruxes can bedazzle the mind of those around them, though they seem to only be able to focus on one person at the time. Are you all proficient with Occlumency?"

"Yes," answered Regulus without any hesitation.

"I think so, but I've not really been up against many Legilimens," answered Severus.

"I've never tested my shields against a subtle Legilimens," answered Jonathan.

"All right. I am a Legilimens," revealed Augustus, earning an impressed whistle from Regulus. Arts of the minds were not common though Slytherins were the ones to learn them the most. "If you agree, we will have a session where I will test your shields. It will also be useful against Lord Voldemort who is an exceptional Legilimens."

They all agreed without hesitation, and Severus marvelled once more at the trust his friends were putting into him. At the trust himself was putting into his Grandfather. It was ironic to think he trusted the man with his life yet could not accept to swear him allegiance. Loyalty and Duty was a motto he could have followed. But he could not forget how his Grandfather had failed him. A Head of House's words were law for his members. He could not give the man such power over himself. Even Lucius might not be up to the task. Especially now that Severus knew of the possibility of creating his own House.

"Another effective protection against mind control which might also work to attenuate the Horcrux's control on you is the Patronus spell," added Augustus, bringing Severus' focus back on the problem at hand. "Do you all know the spell?"

"Yes," answered Jonathan and Regulus in unison.

"I don't," said Severus quietly. "Lucius is supposed to teach me the real way."

Regulus nodded.
"Without all the happy memory crap right?"

"Exactly."

"We could use a reunion with Evan and Lucius for you to learn the spell Severus, and us to brush up on it," proposed Jonathan.

"Excellent idea if we manage to schedule it," agreed Augustus. "Now that this is out of the way, what other method do we have to find the Horcruxes?"

"I think we could try to use a pendulum," said Jonathan.

"Not the most precise method," remarked Regulus.

"It depends on the ability of the wielder," replied Augustus. "Severus?"

He was thinking furiously. Pendulum were notoriously used by frauds—also known as seers—to communicate with the dead, predict the future and other such impossible feats. However, it could also be used in finding rituals and spells to focus Magic and improve the precision of the results.

"I don't know if I will be able to... well... link each Horcrux to the pendulum. I need to try to see if it works," Severus finally answered. "But it might depend on the pendulum I use too. You know that the material and runes engraved on it can alter their workings."

"I brought several if you wish to test which one gives you the best results," said Jonathan, ears reddening slightly.

"Where did you get them?" asked Severus, curious, as his friend took a pouch and got out no less than eight different pendulums of various size, weight, form and material.

"Mother likes to dabble with farseeing. It's a family tradition, especially among the women," answered Jonathan with a shrug.

Regulus whistled in surprise.
"You have some nice specimens. Mother would be jealous."

"Your Mother believes in this too?" asked Severus, incredulous.

"She especially enjoys reading the future through entrails and blood," answered Regulus as he examined the pendulum. "She would love this one. As black as our name. Do you know where I could get it?" he asked, turning to Jonathan.

Augustus cleared his throat.
"Not really the time Regulus. I know Lady Black's birthday is in two days but surely you already bought her gift."

"I may have forgotten in the excitement of Severus' return and then the panic over the Horcrux problem," answered Regulus sheepishly.

Severus rolled his eyes to himself as his Grandfather and his friends debated over the best place to find or order unusual pendulums.
Kea seemed similarly bored by the conversation as she jumped on the table where they had put the pendulums and began playing with them, pushing them with her cat paw. A glance at his companions showed Severus that they were very much engrossed in their talk. Shaking his head to himself, he got closer to the table and scooped Kea in his arms. She immediately began purring and huddled against him.

"You're lucky I'm not jealous," Sensed Dhaal playfully.

"You are jealous," Sensed back Severus, "but you know you have nothing to fear from Kea, if only because she loses so many hairs Tuei would never allow her in the house more than 5 minutes."

His familiar snorted softly, drawing Kea's attention to him. She rubbed her head against Severus' chin one last time then jumped down to join Dhaal.

He was really glad the two Familiars liked each other.

Smiling to himself, Severus turned his attention back to the task at hand. He peered over the pendulums, Sensing them over, trying to determine the one which could suit his purpose.
The first one was a round dark blue lapis lazuli. It felt peaceful and balanced, but without any goal. It did not react to Severus' prod. The second was also blue but smaller and lighter. Apatite. It reacted to Severus' solicitation, giving a sense of openness and connection. It might help Severus link to the Horcrux echoes. Maybe too much. The next one was in Fir wood with several runes engraved. It felt stubborn and wilful, too rigid for Severus' taste. The fourth one was red like blood, a jasper stone. It felt strong and balanced to Severus but with too much vitality. The next one was intriguing, a common white quartz through which magic flows coursed evenly, making one circle in it before coming back out. Severus doubted it could help him find the Horcruxes but noted in a corner of his mind to study white quartz interactions with magic flows later. The sixth pendulum was the black one which had intrigued Regulus. It was in black tourmaline. Severus immediately Sensed a protective feeling coming from it, as well as the willingness to capture any wrongness. Really useful. Tourmaline might work even better than jade for Petunia's protective stone. He put the thought in a corner of his mind. The seventh pendulum was in green aventurine. Severus Sensed peace yet vitality coming from the stone. It reached toward his main Khorlo as if to invigorate it. He prudently protected himself from it, once more noting to study it later. The last pendulum was a green malachite with black veins. Severus Sensed a profound desire to heal and purify.
Thoughtful, Severus took the apatite pendulum as well as the tourmaline one. He hesitated then took the malachite one as well. He breaded their threads together, creating one big pendulum with the three smaller ones. He had to start anew three times to position them one under another, the apatite closest to him then the tourmaline then the malachite.

When he lifted his head to tell the others he had a pendulum to try, he saw they had put a large detailed map of England on the enlarged table. They were looking at him expectantly.

"Jonathan. I will use your Mark to begin with."

His friend nodded, coming to stand in front of the map beside Severus. He took the pendulum in his left hand, Jonathan's arm in his right. He Sensed Dhaal's alertness and confidence in him. Breathing calmly, Severus Sensed for the first echo. Lord Voldemort's presence was overwhelming the echoes once more but Severus knew what he was looking for. Pushing the Lord's Sense aside, he reached toward the faint presence behind it. There. He grasped one thread only to have it slip from his hold. Severus shook his head at himself while Dhaal Sensed him a stern admonition. It was exactly what had happened when he had first tried to flow-travel. As Dhaal had told him time and time again, the tighter you held Magic, the more slippery it became. It was the same with Sensing spells from one's opponent. You did not so much yank the flow from him as gave the flow a better path to follow, the better path being the one with the clearest intent and focus.
Severus tried again, this time only coming into contact with the echo's thread. Then, he tried to Sense a link between the thread and the pendulum, focusing on the only question which mattered: where are you?
Several times, Severus faltered and felt the link break between the echo and the pendulum. Each time, he created it again. Until finally he Sensed a kind of communication between the thread and the pendulum. It began turning, hovering over the map then suddenly snapped toward one point.

"Lancashire, Silverdale," said Regulus, taking notes on the wall board. "Should we give you a more detailed map of the area to narrow down the location?"

"Yes."

Severus waited, keeping the link open while Jonathan and his Grandfather put the new map into place.
Once more, the pendulum began turning over the map before snapping to a precise point.

"Hmm. On the seaside. Morecambe Bay," commented Regulus as he dutifully noted the location on the map and the board.

"Next?" asked Jonathan.

Severus nodded. He moved his Sense away from the first thread and focused on the next one. It was easier this time.

"Weird," said Regulus. "It looks like this one is in Wiltshire, close to Malfoy manor."

"It cannot be a coincidence," agreed Augustus. "If Lucius is in possession of one of the Horcruxes..."

They might have to let him in on the secret. Severus pushed the thought aside, focusing on the echo.
The pendulum hovered over the more detailed map, circling over and over again.

"The wards must be interfering," said Jonathan.

"Yes, but Severus is keyed to them. He should be able to go through," replied Augustus.

His Grandfather was right. Except Severus was only providing what was necessary to create the link between the echo and the pendulum. He had carefully distanced himself from the echo to avoid any contamination. To go through the wards... Hmm... He could use the pendulum and Sense through it without touching the echo´s thread... In fact he should Sense through the Apatite, as it had felt really opened and ready to help connections.
Nodding to himself, Severus carefully kept the link between the echo and the pendulum while Sensing through the Apatite his will to pass through the wards and confirm the Horcrux presence inside Malfoy manor or not. The pendulum circling lost speed as if hesitating then suddenly snapped to the exact location of Lucius' home.

"Well. I don't know if it will make our task easier or more difficult," said Regulus as he noted down the Horcrux location. " I wonder if—"

"Today, we only are locating the Horcruxes as precisely as possible without approaching them," interrupted Augustus firmly. "How to retrieve them without damages to ourselves will be the subject of later meetings. I remind you there will be no attempts until I deem you proficient at Occlumency and Patronus. Moreover, we will scout out the various locations and analyse their defences before even entertaining the idea of retrievals."

"Yes Sir," they agreed in unison.

"Next one Severus?" asked his Grandfather. "Or do you need to eat something?"

Severus took the time to check himself before answering.

"I could drink some hot chocolate," he admitted.

His Grandfather did not seem surprised.

Of course, Tuei was unable to only bring hot chocolate. Once they had all plied themselves with cookies and tea or hot chocolate—Kea was as gourmand as Dhaal—Severus went back to his task.

It was easier this time, the pendulum immediately snapping to Lancashire. The enlarged map showed the Horcrux was precisely located next to Little Hangleton, a small village.

"Why would he put it there?" asked Regulus puzzled.

"Childhood fond memories?" proposed Jonathan.

"Because nobody would look for it here?" suggested Severus.

"Does it really matter?" interrupted his Grandfather.

The three of them shook their heads sheepishly.

"Last one Severus."

Severus nodded. The last thread was the hardest to reach, feeling less tangible than the others. When Severus finally managed to establish the link between the echo and the pendulum, it turned on itself, hovering over the map but never choosing a definite place.

"Hmm. From the area covered by the pendulum, the Horcrux seems to be in Scotland," said Regulus dubiously.

"I would bet on Hogwarts," added Jonathan.

Regulus looked at him with interest.
"Really? I admit the concept of hiding a Horcrux here is interesting if you're certain nobody will find it."

"You know there are many unexplored rooms and secret passageways. Lord Voldemort is Slytherin's descendant. He might have found his secret lore," answered Jonathan.

"Let's say it's Hogwarts for now," said Severus definitely. "We'll need to confirm it by going there behind the wards one way or another, but I agree it's coherent with Lord Voldemort's spirit and the castle's wards would explain why the pendulum was lost."

He turned to Regulus.
"Regulus, I would like to check the locations with your Mark please."

The verification was quick and confirmed the locations Severus had first found with Jonathan's Mark. To be certain, he also tried other pendulums. When they did not turn aimlessly over the map or stubbornly remained stuck to the table itself, they gave less precise results than the first pendulum but confirmed the overall areas they had already defined.

"Good work boys," praised Augustus. He looked at his antic pocket watch. "We need to call it a day. Madeline is waiting for me."

He grimaced.
"I promised I would escort her to Lady Sinistra's art exposition."

Regulus groaned.
"I promised Mother I would go too."

Lady Sinistra was known for supporting unknown artists. She loved all arts and encouraged creativity with generous donations, however her expositions tended towards weird or ugly.

Augustus nodded.
"Olivia is lovely but her tastes are quite unique. Madeline once found a painting she liked at her exposition thirty years ago and insists we go each time. At least, it provides gossip for a few days."

"Rumours are her new favourite was inspired by muggle painters," said Regulus with disgust.

Augustus looked at him sharply.
"Some muggle artists are truly talented. You should see some of Michel-Angel's or Monet's creations."

"Sorry," said Regulus chastised. "With everything going on, it's getting harder not to put everyone in the same basket."

"If we were judged only on Vladinka's or Grindelwald's actions, all Wizards would be monsters."

Augustus was right to insist. Severus would have found it difficult too if his father had been his only reference. His correspondence with Petunia gave him another insight he was grateful for.

"Do you know Muggles sent a man on the moon?" asked Severus.

"Sent a man on the moon?" repeated Regulus. "How?"

"And why?" added Jonathan perplexed.

"They used what they call rockets," explained Severus. "It's very complicated and expensive. They did it about ten years ago. To show they could I think. And to explore."

"I still don't understand why they would want to," said Regulus.

"I wouldn't even think about it," agreed Jonathan.

"Muggles are very curious about the world around them," explained Augustus. "I think it's because of their lack of Magic. We are mostly focused on Magic functioning and its impact on our environment while they try to understand how the entire world works and how each element relates to the others."

"I spoke to a Werewolf during my Apprenticeship who wondered if he would instantly transform and remain in wolf form if he went to the moon. It made me wonder if there is Magic on the moon. If Magic exists everywhere," added Severus.

"You think they are looking for a place where they could put us without worrying about our powers?" asked Regulus horrified.

"No!" exclaimed Severus. "They don't even believe in Magic, except for a few exceptions. However, they believe other planets like Earth exist in the universe where other intelligent species live. They want to establish contact with them."

"If they're right, it's dangerous! Why would they do that?" asked Jonathan puzzled and a bit alarmed.

"They believe any aliens would be benevolent," answered Augustus. "Not the most logical point of view I agree. However, I am in immediate danger because I know Madeline is waiting for me," he reminded them.

"Of course, sorry Augustus," said Jonathan.

They left quickly, leaving Severus to ponder Muggles, Magic and Sciences. It already was on his to-do list.