As always, I own nothing relating to Tolkien.

It hadn't always been this way, she remembered. When she first married him, their halls had been filled with laughter and music, and her husband had been warm and loving. Now those same halls were gloomy and gathering dust; it had been nearly a year since any guests had been invited, or her husband had lain with her. He had turned over more and more of his ruling duties to his steward, preferring instead to stay in his chambers or leaving on journeys at the behest of his Master.

"You are a king," she had said, shocked, the first time he had mentioned his Master. "You should not serve another."
"Lalaith, there is so much you still do not understand." Her husband's eyes had started to lose their youthful gleam. "My Master, Lord Sauron-" -she hated the way he said that name, mouth caressing the syllables in the same reverent tone she had thought was reserved for her alone- "-you should hear him talk. He can give me - give us - such power. I know you hate it when I leave for so long, but soon the world will fall at our feet. I will be a king of kings, and you shall be my queen." It frightened her when he talked like this, but then he had kissed her for the first time in months, and for a time all her worries melted away.

When he had returned from his journey, Lalaith had noticed the golden ring upon his finger, but had dared not ask him about it. Besides, there were other, more worrying changes in her husband. Even the weak winter sunlight had become too much for his eyes to bear, and he started to dress himself in a long black hooded cloak, even inside. He would lock himself away in his study for days on end, and would not eat. His trips away from home became longer and more frequent. Often he would be gone for months, and stay for only a day before leaving again. Finally she confronted him.
"Handarwë, what is wrong with you?"
"Nothing is wrong with me, Lalaith. Now leave me be. I am very busy."
"My love, you hardly live here anymore. You don't eat, you don't sleep, you won't see me..." her voice cracked. "Whatever Lord Sauron is forcing you to do, it cannot be healthy, it cannot be good. Maybe I can't do anything, but I can help you share this burden. Just tell me what is happening to you." Her husband's expression was cold, and tears welled in her eyes.
"Lalaith." He caressed her face. His hand was ice cold. "There is something you can do for me. Lord Sauron wishes to have nine servants at his command. I am the eighth. You could be the ninth." He drew something from his pocket - a ring, similar to the one he wore. Lalaith shook her head and started to cry in earnest.
"Think of what we could be together. Take the Ring, Lalaith, and your name will live on forever. You would be a queen of queens, the strongest, most beautiful woman in the world. You could stand by my side and watch a new era begin. Just take the Ring and swear fealty to Sauron. It is such a small thing to do, such a little thing."
"No." Lalaith shook her head again, but there was a part of her that was starting to doubt. She knew her husband was mad, that he was being deceived, but the future he painted was so compelling that she couldn't help wonder if she was wrong.
"Lalaith, please." He voice was low and pleading. "Do you love me?"
"I do." She exhaled shakily, tears running down her cheeks, and slid the Ring onto her finger.