It was no good. Potter was searching for his horcruxes, and that would absolutely not do. But how to stop him?
The Dark Lord paced back and forth. He was not angry, no, just pensive. He could not create another horcrux for fear that Potter would catch on. He was not stupid – ignorant, unskilled, arrogant, half-blooded, yes, but not stupid. And the Mudblood Granger would no doubt figure it out, even if he didn't. What could he do to stop his heritage from fading away?
The answer came to him suddenly, as twilight fell. An heir! Someone with his blood, his soul to carry on everything that the Dark Lord stood for. And the plan was formed.
He came upon the poor pureblood in the middle of the night. He performed the work without remorse and left, never looking back. There was nothing inside of him to feel anything, but at least is legacy would be carried on. He would destroy the child and its mother when the battle was over. After all, this was just precaution.
That was January 1998. Now it's October. And the Heir of Slytherin was just born into the world, a helpless child. His father is dead. He has no idea who he was or what he did. Or that in twenty-four years' time he will be at the forefront of a revolution, bearing the mark of Lord Voldemort.