Story Disclaimer: This is JKR's beach, and I'm just wading in the water.
A Dark Fixation
You're scared of me because you think I'm evil and wicked. Well, maybe I am, but I wasn't always that way. I didn't always have such a sinful, criminal mind. In fact, there is only one reason that I turned so wholly and thoroughly to the dark arts. That reason is Tom Riddle.
When I was in school, I would visit Tom outside of the village on Hogsmeade days. He'd teach me things I would never learn inside the secluded, sheltered walls of Hogwarts. Those days were precious to me--because I spent them with Tom.
I became very possessive of my time with him. Lucius Malfoy, my sister's husband (boyfriend at the time), wanted in on my lessons, and Tom accepted him. I don't think I've ever been so angry in my life, but that anger came to good use when Tom told me to duel Malfoy. He trashed and writhed on the ground like a snake caught on fire. And I laughed, proud of my accomplishment. But I wasn't the only one who was proud.
After seeing me duel that day, Tom seemed to respect me, and he vowed to make me the most powerful witch in all of the wizarding world. He told me that I could stand along side him. Tom Riddle, my beloved mentor, wanted me, Bellatrix Black, to stand along side him as he took over the entire world! I was beyond happiness--I was at the point of rapture.
By the time I graduated, he had complete control over me. He was gaining more and more strength, he was gathering more supporters... He changed his name to Lord Voldemort. All of his followers, including myself, were considered his Death Eaters and were to answer only to him. We addressed him as the Dark Lord.
I can still remember the first time he addressed us all, as his Death Eaters.
He stepped into the dimly-lit room, his footsteps echoing on the cold, stone floor. I saw him gaze around the room, and felt myself flush as his eyes landed on me and I bowed my head to him, as I had done so many times before during our lessons.
"Hello, my Death Eaters," he said, his cold, harsh voice, captivating me. The power that surged from him was so intense, so extreme. How I wanted that power.
"This," he continued, motioning around vaguely, "is my fate; I will destroy all muggles and muggleborns, so that purebloods may raise to power once more. We will regain what is rightfully ours... A fixation of the dark arts has lead me to all of you."
A fixation of you has lead me to the dark arts, I thought to myself. This was the first time I realized that I had lost control of myself. But I couldn't have, because I believe everything Tom was saying; I believed that mudbloods were scum and I hated that the wizarding world was being overtaken by them. I was right to be here. I was.
After that small assembly, I convinced myself that I was right, and that being a Death Eater was right for me. Killing wasn't a problem for me. Torturing had no affect on me. I was glad to be at Tom's service.
I soon married a man by the last name of Lestrange. But not for love. No, it was for the mere sake of pureblood respect. The man I call my husband is nothing more than a man whose last name I have stolen. He has no real part in my life, other than being a fellow Death Eater.
After years of being a devoted servant, I knew I had no chance of ever standing alongside the Dark Lord. I no longer called him Tom. I no longer bragged about the time we shared before his great rise to power. I only existed as a servant. The one thing I resent is being his servant.
I am the most powerful witch. He has fulfilled that promise. But I did not rise with him, I crawled with his other vermin-like servants behind him, wishing to be declared worthy of kissing his feet.
I did everything I could to get him back when he was taken from us by Harry Potter. I was thrown in Azkaban for him! I suffered years in that hell hole, and I accepted that life as my duty! And when he finally did return, I was rewarded by being told that I was faithful. Doesn't he think I know that? Doesn't he think that I am aware of my own faithfulness?
But I think the most pathetic thing about my life, is that my finest moments all consist of me being rewarded by the Dark Lord, like a dog. Being branded with my Dark Mark, being called his "most faithful servant." And like a dog, I am never going to be returned the love that I still give my owner. Because not only does he own my soul and life, but my heart as well. And that's something he will never give back.