Disclaimer: The world belongs to Tolkien; the words alone are mine.
A/N: Thanks to Claudia for the beta!
There was not a time in her life when she did not remember having him watch over her. As a babe, she remembered that he would sing songs that made the breeze twist and rustle through her hair, that quieted storms, that called birds to her windows.
Later, his song calmed the tears that flowed when her brothers teased her. It was the accompaniment to which she danced, bare feet on warm earth, wild and free. It was when she danced that he named her Tinúviel.
She never truly saw him, although she knew he was tall and dark haired, cloaked in grey. If she looked straight at him, he would disappear, fading into the starlight. At first she had been worried that Adar or Naneth would catch him. Adar, in particular, had gained the peculiar habit of peering into her room when the singer came, as if looking for something.
Arwen once asked him if he feared discovery, but he only replied:
"I am not the singer your father seeks, Tinúviel,"
and would speak no more of it.
When she was a child, he taught her of the joy of song.
Later she grew beyond the fear of storms, became more friend than adversary to her brothers. She wandered less often in the gardens; a love of learning took her, and many quiet evenings among the libraries of Imladris were pleasantly spent in the company of the lore of old.
He came less often, then, but yet on still nights she would hear a scattered snatch of song, a melody riding on a gust of wind, a call – "Tinúviel, Tinúviel."
She asked him if he thought she would succumb to the same fate as Lúthien; he said that he had given up interfering in the fate of others. She asked him if he regretted his actions; he said he did.
When she was older, he taught her how to tell when someone was lying.
The first time she heard him outside the boundaries of her father's lands was by the sea. He showed her the anger beneath a brother's tears, the blame her father had laid upon himself. The song explained to why her mother wished – nay, needed – to depart, and she nodded, and understood.
He lent her words when she could not find her own; helped her find a way to say farewell to one who was both friend and mother.
By the sea he taught her how to find strength in sorrow.
For a long time, she heard him not. Perhaps he thought he was no longer needed; it might have seemed that way. She cared for her father, softened the hurt in the hearts of her brothers, and waited.
She was not sure what she was waiting for, but that was all right. A long time ago, one of the first things he had taught her was patience.
He came to her again in Lórien, when she had found love unlooked-for.
"And so your fate is sealed," he said, and for a while she did not reply.
"Why did you betray her, if you loved her so?" she asked.
"I betrayed her because I loved her," he replied. "And loved myself less for my betrayal."
Arwen smiled. "Perhaps it is true then, that all lovers are fools," she said.
"You are not a fool," he replied, and she knew better than to ask him for anything more.
In Lórien, he taught her not to doubt the strength of love.
In Lórien again, he speaks for the last time. He sings her a song to calm the storm of her grief, the melody wrapping her round, and she is no longer cold, and she is no longer afraid. The autumn leaves are falling, tangled in her hair; she dances again with bare feet on warm earth, and he laughs.
She sees him then, for the first and last time, as he would have been once upon a time: tall and grand and shining, dressed in the green and grey of Doriath. He bows low, and smiles.
"Go to him," he says, and beyond him the door is opening, and Estel is waiting. "Go to him, Tinúviel."
And so she does, but before she goes, she whispers a secret in his ear, looks to see he understands before she ascends, all the pain gone, all the sorrow but a distant memory.
Before she went, she taught him of forgiveness.