The first order of business for Harry was learning how to read minds at all.
Legilimency was one of those things that, while not being directly filed under the Dark Arts (with all the baggage that entailed), was quite closely associated with them. Reading another person's mind was not something that lent itself to many purely selfless practices, after all. That meant all the texts Hogwarts had on the subject were buried deep in the Restricted Section of the library. Such a precaution probably wasn't enough to stop any kid who really wanted to hurt someone, but it was better then nothing.
A large and incredibly obvious problem arose when Harry went over the most basic information on Legilimency. The magic around it was closely based around proximity between the person doing the reading and the person being read, which made the task Harry was attempting to do seem utterly impossible. How could one perform a spell entirely revolving around eye contact when the other person was not even in your field of vision? Yet it clearly had to be possible, as Harry had previously been able to observe Voldemort from miles and miles away before.
Dumbledore, as usual, only had a mystical sounding theory to offer.
"I would try focusing on the part of you that is most connected to Voldemort as a substitute for his eyes. I would guess that the scar upon your forehead would be the best place to start."
It sounded like as good a plan as any, although there really wasn't any special reason why Harry's scar would be the key to their mental connection. He had never noticed anything unusual about it before.
Harry did not make any progress on finding the connection until the fourth night he spent looking for it. The books he had were written under the assumption that a connection between minds would be created by the person using it with a spell, which was quite hard to miss. Nevertheless, it did describe what such a connection felt like in enough detail that Harry had a basic idea of what he was looking for. It was supposed to be strong flashes of the emotions the person on the other end of the connection was feeling, with thoughts being too large and complex to be identified in the brief bits of time in which they were detectable. In Harry's case, the emotions coming from Voldemort were much more faint then the book described, and quite rare as well. There would only be brief twinges of anger here or happiness there, like tiny, ghostly pains that were gone before they could be truly felt. The Occlumency training Harry had went through proved itself to be quite useful, as those twinges were much easier to spot when his mind wasn't filled with disconnecting thoughts jumping all over the place.
Further research into the topic of Legilimency also revealed interesting things about the connection Harry and Voldemort had. The book was based almost entirely around mental connections that only flowed in one direction, as a two way connection would theoretically be just as useful to both parties rather then just one. The mind reading spell was designed so that one person would access the other person's mind while the other person was incapacitated, so the authors of the book never considered that there might be a situation where two people might try to read the other's mind simultaneously.
Great. Now I can add 'walking case study' to the list of descriptions I never wanted to have next to my name.
Really, when Harry thought about it, he realized that it was like some kind of stupid romantic story where two people fell in love and somehow produced a psychic bond that allowed them to share all their thoughts together as if they had one mind and two bodies. If the tabloids ever got a hold of that story, then the results would certainly be migraine inducing. Harry could imagine the headlines... "Boy-Who-Lived shares soul bond with Lord Voldemort, the most evil wizard since Count Chocula."
Once Harry had found the connection, the next step was to try and follow it to Voldemort's mind, so he could listen to the thoughts that passed through it. Here, the book was again unhelpful, for this sort of work was designed to be done through the Legilimens spell. The spell would do all the hard work of creating the connection and getting the caster into the other person's mind, and by typical wizarding standards, no one had bothered explaining how the spell actually did that in the first place without it being buried under pages and pages of surface integrals. Being as unaccomplished in math as he was, Harry was stuck with the old standby of trial and error.
When he wasn't busy with Legilimency, there were now meetings with Dumbledore's secret anti-Voldemort society to deal with. These were often held at Sirius Black's old apartment, and it was quite jarring at first to see a resistance group discussing how to protect muggles from wizards a room away from a crazy portrait who would not stop screaming about mudbloods and filth being allowed in her house.
The meetings themselves rarely held good news. It was always gloomy whenever someone would step in to inform them that another muggle family had murdered in their homes, another wizard known for their pro muggle beliefs had gone missing, or the Dark Mark had appeared in yet another ominous spot. Snape, who turned out to be a spy for Dumbledore (in hindsight, Snape certainly did look the part), also came with grave news about the future of wizarding England. Voldemort was contacting his old allies, the giants and the wild werewolves, and the Order's attempts to court these factions had failed. The Dementors of Azkaban were looking to be the next on that list, and there was little the Order could offer to them to keep them working for the Ministry. Fudge himself was looking to resign as his attempts to combat the Death Eaters ended in failure after failure.
All of this made Harry question the importance of hunting down Horcruxes. Being able to completely kill Voldemort was a plus, but it wouldn't mean much if they had no chance of getting to the man in the first place if he ended up taking over the Ministry. Even if Voldemort was rendered mortal, what would it matter if he overthrow the government and began ruling the country as he saw fit anyways?
Still, Harry pressed on with his task, because it was the only way he could see himself making any kind of difference in the grand scheme of things.
After attempting all sorts of things to try and follow the mental connection to Voldemort's mind, Harry found the one that would get the best results by tiring himself out and trying to doze off during the day. This would result in him fitfully drifting in and out of a dreamlike state where the connection felt like it had a physical presence to his mind that he could follow somewhere else. Actually choosing to follow it was tricky, as while he was dozing, conscious actions proved themselves difficult to make. Nevertheless, enough attempts would allow his mind to follow the connection, and then he would be close enough to Voldemort's mind to listen to some of his thoughts.
Listening was the word Harry would use to describe it, as it was far too patchy and irregular to be called reading a mind. Harry's first successful attempt at listening to Voldemort's mind brought in only a few fractured sentences and a fuzzy image of a bearded man in a dark room.
"... how are - -le after re-ng them from Azkaban?" something that sounded like Voldemort had said.
"... Lestranges recovered, but - needs ... two suicides..."
"... next - has to ... - - for..."
Still, the information that was given there proved to be correct when Snape confirmed that two of the Death Eaters that had escaped in a mass breakout of Azkaban had indeed killed themselves. Given that most of the people there had spent thirteen years living with only the company of Dementors, Harry was surprised the number wasn't higher.
The initial excitement over having made a breakthrough in using the connection quickly faded as Harry grew accustomed to how useless it usually was. It was like trying to recreate the entirety of a radio program that ran at a specific time of day every other week using randomly selected snippets from programs from every time of day, which were also partially filled with static. And there were times when Voldemort's mind was completely closed, or the connection would open when Harry was in class or asleep and couldn't use it... the tidbits of information Harry had collected hardly amounted to anything. There was something about a shop hosting strange artifacts, the face of a little fat boy in terror, a sword that had escaped its rightful owner, a note that the most faithful servant was driven by love and had to be kept on a short leash, and the image of a ruined cottage with snakes on the door.
None of those things meant anything to Harry, but Dumbledore took great interest in the first and last ones.
"I have been keeping myself busy with detailed research into Voldemort's past, and those two things may be the key to what I'm looking for," Dumbledore had said. "I'll have to look this with one of my contacts in the Ministry."
In a few days Dumbledore was certain he had found the clue to one of the Horcruxes.
"Voldemort so far has displayed a habit of making Horcruxes out of items that have some sort of personal significance to him. His dairy, proving that he was the heir of Slytherin, and a legendary artifact of Rowena Ravenclaw's, which is tied to one of the four founders of this school. And Voldemort's old family probably had some trinkets of their own, which is why we'll be visiting their old cottage that you caught a glimpse of. I had heard of the place before from the old owner's history of attacking muggles, but I hadn't made the connection to Voldemort beforehand," Dumbledore said.
"A question, sir. Why do I have to go with you?" Harry asked.
"I fear there may be a possibility Voldemort has trapped the area in such a way that he might be alerted to my presence if I were to go there. I will try to look for such things, but it would help if you could keep a close eye on his mind in case I miss any. I assure you I will be able to keep you quite safe if given ample warning of Voldemort's movements."
Harry sighed. "Okay. But could we at least bring a couple of aurors along with us, for backup?"
Dumbledore frowned. "I would like for as little people as possible to know of the existence of Voldemort's Horcruxes. If any word were to get out about them, Voldemort would be sure to move them to a place where we might not ever find them again. Then all would be lost."
"You were already risking that by going to a place that was potentially rigged by Voldemort himself."
"True, true. Still, I don't believe it's worth the risk to bring anyone else along who isn't necessary for our operation to succeed."
"Well, you don't have to tell them you're specifically looking for a Horcrux. Just tell whoever you're bringing that you're looking to destroy a very powerful cursed artifact Voldemort hid somewhere that he might have need of one day. That wouldn't even be lying."
Dumbledore raised an eyebrow. "How devious of you, Harry."
Dumbledore, Kingsley, Moody, and Harry apparated to a run down part of the woods bordered by a hideously quaint little village. As they walked down a path leading to the cottage that was apparently so important, Harry noticed that a number of snakes were watching them as they went by. They probably were worried that the newcomers were going to nail them to the door as well.
Nothing seemed out of the ordinary as they approached the cottage, which looked even filthier and degraded then it had appeared when Voldemort had thought of it. There was no traces magic that any of them could detect, save for one noticeable magical signature that was located underneath the floor of the cottage. Not that such a detail would have mattered, as the floorboards had rotted away and exposed a suspiciously clean black box. No suspicious signs from Voldemort's mind appeared as Dumbledore levitated the box up.
"I fear I may have raised your expectations for this outing a tad too high," Dumbledore said. "It appears even the Dark Lord Voldemort has his moments of... procrastination. He hasn't bothered guarding this cursed artifact at all."
Dumbledore opened the box to reveal a ornate ring with a dark green stone embedded in the center. At the sight of it he suddenly seemed to be put into a trance, and walked forward with his hand outstretched, as if he was going to put the ring on his finger. He would have succeeded at that too, if Moody hadn't lunged and dragged him backwards.
"What the hell are you doing, Albus?!" Moody shouted. "What's the first rule of curse-breaking? NEVER! TOUCH! THE! DAMNED! ITEM!"
After being shaken around by Moody and Kingsley for a bit longer, Dumbledore seemed to regain his senses.
"Forgive me, Alastor," Dumbledore murmured. "I seem to have succumbed to that errant foolishness we all face in our old age. I thought... well, I'll tell you about it later. You seemed to have saved me quite a bit of trouble."
"You're right about that," Moody growled, muttering a series of incantations while jabbing his wand near the ring. "This thing was carrying quite a nasty curse. So nasty that if you had put it on... well, the only parts left of you would be your shoes."
They didn't have the time to break the curse right then and there, so they put the ring back in the box and took the box with them back to Hogwarts.
The next Horcrux was not found through any of Harry's poor Legilimency, but instead from more of Dumbledore's research. This time, the four Order members ventured forth to a little place by the seaside, which was near where Voldemort had grown up in an orphanage. It seemed to low key for Voldemort, but Dumbledore disagreed on that point.
"He sees great significance in even the smaller parts of his life, for to him they are the pivotal moments in his rise to greatness," Dumbledore said, as he extended a magic rope leading from a cliff down to the ocean shore. "He used to bully the other children here, and his first abuses of power must have lead him to his greatest ones. Or something along those lines."
They continued from the rocky outcroppings near the shore to a dim underground cave, which left everyone soaked and harboring a newfound appreciation for the difficulties of fishing,
"And here is an actual barricade Voldemort has left for us," Dumbledore said, motioning to a completely ordinary stone wall. "He thinks that most wizards are so squeamish that they would not dare to injure themselves in the slightest, for this door requires a bit of blood to open. He may very well be right, too. Shall we draw straws?"
Kingsley was the unlucky one who had to prick himself with a hastily sharpened stone, which ended up revealing a completely unordinary rock archway. They continued to find an underground lake, which was smooth as the rock surrounding it, and glowing an unappetizing shade of green.
"Now, we have to ask ourselves: where in this lake might Voldemort have hidden a precious magical artifact? I have two guesses..."
Dumbledore trailed off and began fidgeting with the air around the lake, until he suddenly procured a thick green chain from nowhere.
"Clever!" Kingsley said.
"I never would have noticed that," Moody muttered.
Dumbledore pulled on the chain, which slowly summoned a nondescript wooden boat to the shore.
"It seems Voldemort placed his keepsake somewhere at the center of the lake. The only problem is that this boat can only take one of us at a time. I think I should go first," Dumbledore said.
"After that reaction you had to the ring?" Moody grumbled.
"Once burned, twice wise. And I doubt there could be anything as tempting waiting for me as the ring was."
So they slowly trekked across the lake in the boat, one by one, with no suspicious activities from Voldemort once again. The man clearly had no idea what good security looked like.
At the center of the lake was a small island, where a pedestal stood with a basin at the top. The basin was filled with a yellowish-greenish liquid that looked a bit like chlorine gas. At the center of the basin was what looked to be like a bit of jewelry.
"And now we have hit another impasse," Dumbledore said. "The protection provided to this item is quite secure. It does have one specifically designed weakness, but to test it might be fatal. There is a potion in that basin, and the only way to get rid of it would be by drinking it."
"Are you sure we couldn't just brute force it?" Moody asked.
"It would take a lot of time and it would make a lot of noise. Neither of those are desirable outcomes, I'm afraid. Hmm."
"I was just thinking," Kingsley said. "That thing below the potion kind of looks like this gaudy locket Sirius showed to me when I was at Headquarters one day. Said his house elf was bonkers over it."
"And I think I should very much like to see that house elf. Since Voldemort is still unaware of our presence here, I think we can afford to return here with a better plan, rather than fall into an incredibly obvious trap."
So it turned out that the entire outing to the underground lake was a waste of time, and a former Death Eater had already done the dirty work for them, even going so far as to plant a fake Horcrux where the real one used to be so it would not look suspicious if Voldemort returned there. It was an excellent idea, and Dumbledore made a fake ring in a box that he left in the old cottage as well.
Once again in Dumbledore's office, Harry glanced at a table. Their collection of Horcruxes had grown to include a ring and a locket. Looking at the ugly items gathered together, Harry really had to question Voldemort's grasp on aesthetics.
"And now," Dumbledore said, "I would like you to look for any thoughts or memories of Voldemort's related to a small, golden cup. One that used to belong to Helga Hufflepuff."