Unrequited Bellatrix/Voldemort. Italics are lyrics from Simon and Garfunkel's I Am A Rock.
She was raised harshly. The traditions of her family were Dark. Strict and cruel. She knew her destiny. Her future lay before her. She would end up in an arranged marriage to some stupid man. A weak man. She would be expected to bear his children. Such a life held no appeal to her. Of course it wouldn't. Bellatrix Black was a proud girl. She was the best student in her year. What foolish lordling could compete with her and her magical prowess? But Bellatrix was unconcerned. She simply would not allow them victory. She would become so powerful, so Dark, that they would have no choice but to respect her and her wishes. That or face her wrath, she giggled at the thought of the tortures she could bestow upon them.
I have no need for friendship; friendship causes pain
It's laughter and it's loving I disdain
Perhaps if Merope Gaunt had been as powerful as Bellatrix she wouldn't have ended up so badly. Dying in an orphanage after birthing a boy who looked just like the man who had abandoned her. Without so much as a word, let alone a divorce. Then again maybe the scenario would not have changed. It was, after all, determination, a trait her and Bellatrix shared, which had brought her to her ruin.
Don't talk of love
But I've heard the word before
It's sleeping in my memory
Tom Riddle, the younger one, lacked not only his mother's looks but also her quest for love. Rather like Bellatrix he felt no desire for some weak spouse, no need to care for pathetic children. He was a young man, far more concerned with his spells and runes than marriage. He was growing in power quickly. Soon he would be able to whatever he pleased. And the boy did not descend from the great Slytherin line for nothing, he had ambition. He wished for domination of the world, something which was well within his power to do.
I have my books
And my poetry to protect me
Unfortunately for Bellatrix Black, plans have a tendency to fall apart. You may plan to live in peace without love, but it's unlikely to happen. Especially around Riddle men, as Merope could attest to. They had a habit of attracting determined witches. Bellatrix made her desire obvious from the moment she entered his service. He made his disinterest just as clear. Bellatrix, despite being more powerful than Merope, was in love with a wizard, unlike with a muggle, love potions were not a viable option.
If I never loved I never would have cried
From the moment Bellatrix became a Death Eater Voldemort could tell she wanted him – in every way. He could sense the witch's lust for his power, for his violent and inhumane body, for the future he could bring the world, for the children she could bear him. He still felt no need for such a thing. The woman was powerfully Dark, but not as much as he. He was immortal, heirs were irrelevant. He felt no desire for a body to warm his bed. She was his Death Eater; he already possessed her in every way necessary. He fled the woman's insanity whenever he could.
I am shielded in my armour
Hiding in my room
Safe within my womb
I touch no one and no one touches me
Bellatrix grew from the young girl she had been when she took the Dark Mark. The teenager, just out of school who had loved and desired the Dark Lord. Her insanity grew as the years passed and the campaign for the Dark brought fear, but not victory. She married Rodolphus as part of an agreement. They believed her foolish but she knew what the agreement was. Her family saw her spiral into the Black insanity and paid the Lestranges to bring her into their family and care for the "crazy girl". By the time Bellatrix left Azkaban she had lost her joy in both power and love.
And a rock feels no pain
And an island never cries