I gaze off into the distance, not looking at him, as if I can see all the way to my cavern filled with host bodies, deep in the mountains. I knew this conversation would come- someday. I just didn't expect it to arrive so soon.

"Plenty," I say vaguely. The haunting memory of an ancient mirror and the temptations lingering within the clouded glass occupies my thoughts.

He peers at me with intense eyes. "What do you know?" he presses.

"I know," I reply, a bit sharply, "that they're the stupidest way to become immortal. There are at least three other methods that I know of, and none of them involve ripping your soul apart and leaving it lying around in a destructible object."

He opens his mouth, as if about to speak, then closes it again, his brow furrowing. After a moment, he decides to say "What are the other ways?"

I sigh inwardly, both exasperated and slightly amused by his blatant thirst for power. If we're going to talk about this, I think, Let's do it somewhere a little more secluded.

His mind is in turmoil with a sudden influx of rapid questions, but he manages to gain some control and think out: Fine. He's clearly not very fine with it.

We walk, at a somewhat faster pace this time, back towards Hogwarts. Tom lets me lead, and I make my way to the edge of the lake, finally perching on a lip of cold, hard ground overlooking the huge, flat expanse of dark water. I brush my hand absentmindedly over the frosted grass, enjoying the sharp bite of ice on my palm as I gaze at the heavy afternoon sunlight rippling off the lake's surface, like golden tarnishes on a depthless black mirror.

Tom slumps down unceremoniously beside me. I wrinkle my nose at his lack of grace and elegance, but ultimately decide that he must get it from his father, so can't be helped.

"So, tell me, Thomas," I say, a touch patronisingly, "How much do you actually think you know about Horcruxes?"

He bristles at my tone, but manages to stay proud and arrogant as always. "Plenty," he replies haughtily. I raise my eyebrows at that. "I know," he continues, "that you use a Horcrux to contain a piece of your soul that has been split apart from the whole. I know that you split your soul by killing someone and then using a ritual to contain it in an object. And I know that with a Horcrux, you can never truly die."

"Tom," I say slowly, faintly bewildered by his complete lack of common sense and good judgement. "I'm not sure that you quite comprehend the dangers of splitting your soul. The soul is a delicate and mysterious thing. It is not designed to be ripped apart."

He seems marginally taken aback. "But with a Horcrux," he insists, "you can never die! You'd be immortal."

I struggle for a second to find a way to explain to him why splitting your soul is probably the stupidest thing you can to in pursuit of immortality. "Tom," I repeat. "Ripping off a chunk of your soul in order to be immortal is like cutting off your own leg in order to lose weight. You've gained the desired effect in both cases, but at what cost?"

A faint flush rises steadily up his neck. "Well," he says defiantly, "you said you know three better ways to achieve immortality. What are they?"

I'm glad to see that I've begun to sow doubts into his mind about the reliability of Horcruxes, but there's still a long way to go in persuading him that immortality is not all he thinks it will be. I lean back, bracing myself with my hand and squint at the slowly dying sun over the mountains. The fading light casts a faint, reddish shadow over Tom's porcelain face, catching his glacier-blue eyes and making them burn with an intense, cold flame.

"There are four ways that I know of to achieve immortality, or at least, relative immortality," I begin. "The first, of course, is using Horcruxes, which is extremely ill advised, due to the dangerous nature of soul-splitting and the vulnerability of Horcruxes to certain substances. Therefore, Horcruxes don't actually make you immortal, they just make you significantly harder to kill."

I look at Tom to see him listening with rapt interest and an almost fervent curiosity. I'm slightly unsettled, but decide that telling him about this is ultimately beneficial to my cause.

"The second way is drinking the elixir of life from a Philosopher's Stone. This does prolong your life, as long as you continue to regularly consume it, but does not prevent ageing and you can still be killed.

The third way is using rebirth." I pause at this point, wondering how much to tell Tom about my chosen method for immortality.

"It involves very complex necromancy and can take decades to fully master enough to be reborn even once, but essentially you have to tie your life force to this world, usually through an object of some kind. Not unlike a Horcrux," I say, seeing the question arise in his mind, "but without the soul-splitting and infinitely less destructible. This object has to then be an active link between you and the living, often by being kept in the reborn person's bloodline as a kind of heirloom. Once this is established, you can create host bodies to be reborn into each time you die. This way, you don't ever have to grow old, if you don't want to." I pause, and then, seeing the hunger in Tom's eyes, hastily add, "Of course, this only works as long as the object remains in your family and it is possible, though unlikely, that the object can be destroyed."

Tom nods, his face aglow with ardent fascination, his fierce eyes never leaving my face. "And the final way?" he asks eagerly.

"The final way," I say slowly, "is the only way to achieve true immortality. With all the other paths, death is possible, but this way, you can never die, even if you want to." I sigh, remembering the anguished face of a foolish young man, trapped forever in the land of the living, but eternally unable to partake in it. He was right to warn me away from true immortality. "However," I begin again, looking sternly at Tom, "this is no gift. Yes, you achieve eternal life, but you lose everything else in the process. Your corporeal form, your free will, your ability to affect the world around you." I shake my head sadly. "That is no life. Death would be preferable to existence without true life."

"Yes," Tom says, "but how would you do it? Theoretically."

I blink at him. "Did you not hear a word I just said?"

He shrugs. "I'm just curious."

I'm seriously tempted to push him into the lake. However, I resist, and decide to answer his question like a mature adult. "Theoretically," I say, "one would have to complete some sort of ritual in order to separate the soul and mind in their entireties from the physical body, whilst keeping them anchored through some kind of binding spell to the Earth. That way, you would be able to exist in an intangible form in the physical world."

Tom frowns, trying to grasp the concept. Then he says "So you'd basically just be a ghost?"

I ponder for a moment. I've never thought about it like that before, but now that I do, I see that the two forms of existence are remarkably similar. "Yes, sort of like a ghost, in that way that you have no true body. Except," I say, thinking it through as I speak. "no, not really like a ghost at all. For one, ghosts are dead. And for another, ghosts are generally visible to the living and can interact with them. Also, ghosts actually can, very rarely, pass on to the afterlife. With ethereal existence, no form of death is possible."

Despite my best efforts, this still doesn't really seem to be such a bad thing in Tom's mind. I suppose only the immortal can truly understand how death can become welcome after a long life.

"And how, exactly," Tom says suddenly, suspicion lacing his voice, "do you know about this?"

I roll my eyes. "What do you think I do in class instead of studying?"

He frowns again. "You've been doing the work whilst I've been sat next to you."

I give him a pointed look. "Exactly."

"Oh," he says, in abrupt realisation. Then he grins wickedly. "Well, don't let me stop you reading up on satanic rituals during Binns' lessons."

I laugh, half out of surprise as I grasp the fact that he's joking. Tom Riddle, dark lord supreme, is trying to be funny. And succeeding, which is more the wonder. "Satanic rituals are the least of your problems. You should see my books about sacrificial rites."

Now it's his turn to laugh, except this time, he doesn't make that horrible, high, cold sound. Instead, it's lower, richer, more earnest. A real laugh- or as close to one as he can get. I smile, glad to see him relaxed for once and -more importantly- not thinking about Horcruxes.

"But seriously," he asks, "Why don't you study in class?"

I shrug, picking up a smooth, round pebble and tossing it aimlessly into the lake. Receding sunlight dances on the gentle ripples it makes. "Perhaps school is beneath me."

He smirks. "That, I don't doubt." He follows my lead and picks up a pebble of his own, pitching it into the water. "But why don't you have any friends?" The undertone isn't malicious, rather simply curious.

I raise my eyebrows. "What makes you think I don't have any friends?"

"The fact that you're always alone," he replies smoothly. "You never do anything with anyone else unless you absolutely have to."

Maybe Tom has been observing me more closely than I anticipated. Ironic, since I've been the one watching him since his mother died. "True," I say. "Perhaps friends are beneath me, too. Merlin knows you think they're beneath you."

"I have friends," Tom protests.

"We've been through this, Tom," I say patiently. "You have followers. Not friends."

His brows narrow together somewhat even as a corner of his lips tugs upwards, as if he's as confused by my words as he's amused by them. "What are we then?" he asks.

Family, by mind says unhelpfully. Fortunately, I have enough self-control to employ occlumency to prevent him seeing that word in my head.

"Indifferent acquaintances?" I suggest.

He has the gall to look a little put out by that. "We could be friends," he offers, to my eternal shock.

"Unfortunately," I say, still recovering, "I don't think you have the temperament."

Laughter glitters in his sharp eyes, but I still glimpse cunning lingering in their icy depths. Whatever his endgame is with me, it certainly isn't friendship. But friendship is definitely an important stepping stone on the way to my endgame with him, so I decide to play along with his little game for the time being. He grins and shrugs at me, blissfully unaware of my ulterior motive when it comes to him. "Maybe. But we could still try."

I look out over the lake at the setting sun, silhouetting the rugged mountains with a backdrop of blazing crimson, then back at Tom. His eyes reflect the scarlet of the sky.

"Okay," I say.