Spoilers: I really don't think this gives anything but the vaguest of general references to anything beyond Chamber of Secrets.
Disclaimer: All within belong, naturally, to J.K. Rowling. I'd be somewhat amazed if she was taking it in the same direction as this story... but she might surprise us yet.
Oh, the tangled webs we weave, when we practice to deceive...
- Sir Walter Scott
The plan has been a long time in its execution.
A long time, but he has patience enough for it. The gathering of power is never an easy task. Oh, any foolish megalomaniac can gain power, but to keep it, and to hold onto it long enough to accumulate more... such things require careful preparation, and infinite, infinite patience.
There are many sources of power. Knowledge is one. To know things - not just the larger truths, but the inconsequential little things that others pay no mind to... that is power. And a seat of learning is the perfect place to seek it. He is expected to gather knowledge, encouraged to do so. It is his for the taking.
Some may consider power so freely given to be worthless, but he is not a fool. That which is freely given is seldom demanded back. And so he learns. He learns under many masters, not all of whom realise that they are teaching him, or how much. He learns from those who think they are his students. He learns from his enemies, even as he crushes them so utterly that all fear to oppose him.
He learns many things that others do not know. He knows the secret of immortality, and what Salazar Slytherin left behind to guard his Chamber of Secrets. He knows what brought the Dark wizard Grindelwald to power, and what eventually became his downfall. He knows that there are, in fact, many more than twelve uses for dragon's blood, and all of them come back to power.
Blood is power. The blood of innocents is ripe with it... but who is to say, ultimately, what constitutes innocence? Most agree - against all evidence - that children are the pinnacle of it. But one cannot simply murder children. Subtlety in all things; power is nothing if it cannot be maintained.
Dead children are missed; corpses are never as fully buried as you would desire. To shed a lot of blood would raise too many questions. Ah, but a little blood... a little blood is easy to arrange. Childhood is a time of scrapes and broken limbs, and in the wizarding world where injuries are so easily mended, who thinks too long about the dangers? Quidditch is dangerous. Dark creatures are dangerous. Magic is dangerous. Accidents will happen.
A little blood, over time, becomes a lot of blood. It seeps into the earth, flows into the stone of a place. A spreading black stain beneath the surface, under the skin of its history - and darkness begets more darkness. Ghosts, and nightmares, and dark emotions.
Emotions are power, too. They burn hot and reckless in youth, easily stirred, and easily twisted. He likes to work with children. All men are easily manipulated, of course, and he is quite the master, but there is something quite... delightful... about the violence of youthful loyalties. So quickly forged, so fiercely broken; the trust games played in childhood leave scars that burn for life.
Making others act as you desire is a small trick. Shaping them into people who will always act as you predict... ah, that is true mastery. The young are fresh clay, malleable, their fates sculpted with the forces of rivalry, jealousy and insecurity. A casual word here, a sign of favour there; the interactions of his puppets are as choreographed as a complicated dance routine. They are all as much his creatures as the pieces in a game of wizard chess, doomed to move in the directions he prescribes for them. Most beautifully of all, they do not even know he is their puppet-master. They think they act of their own free will; none realise how much control he truly wields over them.
Except Snape, perhaps. He created Snape almost by accident, the consequence of actions in the shaping of another. Yet he has proved one of the most versatile pieces in this complicated game, the one that moves in odd directions, and sends others off at tangents they would never take unaided. Snape loves himself too little to arrogantly assume he controls his own destiny, and he knows full well the master that he serves. But he is still a puppet, for all that, and his strings are easily found. He will do what is required of him, when the time comes. As will they all.
He does love all his puppets, in his way. It binds them to him more tightly than bonds of fear or duty or even self-interest could ever achieve. They are what he has made them; he is father, god and teacher, even to those who no longer acknowledge him.
Control of people is power, but it must be wielded to an end, or it is only empty posturing. He does not push his puppets around purely for sport; his machinations have a meaning, and a purpose. He has a plan. A wonderful, intricate, complicated plan, many decades in the making.
He's really rather proud of it.
All power, when you get right down to the root of it, comes from sacrifice. Innocence must be given up to gain knowledge. Life must be given up to draw blood. Control must be surrendered by one to be taken by another. Power comes from death.
The deaths of living beings are far too small to interest him. All life is fleeting, fragile; what magic is it to kill that which is already dying? True immortality runs through deeper channels than mere veins. He realised early on that the altars of power demanded a greater sacrifice from him. The death of something... larger.
And so, he has set about preparing a worthy sacrifice.
It has taken many decades to bring his plan together. Some things cannot be rushed. Everything must be perfectly polished and perfectly placed, or all his work will come to nothing. You cannot have almost a legend.
For it is this that he has been building. A legend, of the kind that grows and spreads and lives on long beyond the deaths of all its players. A legend, powered by the belief of all who come into contact with it. A legend, which will be ground to dust in its final moments, as he rises up to take control.
Harry Potter. Lord Voldemort. He created them both, shaped them from two halves of the same mould with a perfect symmetry. It almost matters nothing which he chose to be the hero. An accident of history only; Tom Riddle happened to be born first.
Tom Riddle was a subtle, devious boy; Voldemort is built from the pieces of him, a creature with no subtleties, no shades of grey. Evil must be pure evil, and look and sound and taste it; this is what legend demands. And so ingenious, furtive, handsome Tom became a creature of open, repulsive, naked evil. So his name became one that only a true hero would dare speak openly.
And he created Harry Potter. It was so easy to engineer their first meeting; it was he who whispered in Lily's ear the suggestion of a spell that would be a hero's epic origins, he who dictated that Voldemort use a curse that would almost destroy him utterly. All heroes must be tragically orphaned; all legends demand a lull of false security to give their hero time to grow.
It was he who lightly brushed the boy's brow in the aftermath, and left a scar in the shape of a lightning bolt. It was he who made sure that the child grew up unloved and unaware of his destiny. It was he who created the prophecy, meaningless words with the unquestionable ring of fate about them. And it was he who placed the servants of Voldemort in the right position at the right time, nudging the boy along the path to heroism, conveniently disappearing whenever the boy needed to be alone and unsupported. He has crafted their final confrontation, slowly and surely, into a thing of epic proportions.
It is coming very soon now. Everything has been set into motion; it is doubtful even he could turn it aside at this stage. But he has no intention of doing so. Voldemort and Harry Potter must meet. The ground for their confrontation is prepared; Hogwarts School of Witchcraft and Wizardry. Soaked for generations with the blood of children, thick with the shadows of their darkest emotions; pain and fear and betrayal and hatred and despair. There will be much more blood shed, on that day. And then there will come the final battle.
The hero and the villain. The Dark Lord and the boy. The two will meet, and only one will survive. So it is written. So shall it be. This is the legend, and everyone knows this. Everyone. Everyone.
And everyone is wrong. The hero and the villain will meet... and both will be destroyed. Everything will be destroyed. This is his sacrifice, and Hogwarts is his altar.
Others have made sacrifices to power, but all have always thought too small. Albus Dumbledore has never had that problem. For the last seven decades, he's been building a legend.
And soon, very soon, he's going to destroy it.