Winged Voices: Birds of Middle-earth by Himring

Chapter 4: To Music of a Voice Unseen

Arwen is like Luthien, we know.
Not only in Aragorn's eyes, but also in the eyes of those who have actually seen Luthien.
Arwen lays a ghost--no, not exactly a ghost...

Arwen awoke because she heard the nightingale sing—or maybe did not wake, but she got out of bed, climbing through the window onto the terrace, wandering through the warm summer night, following its call, until she came to a glade she had never seen before—or maybe it just looked unfamiliar in the moonlight… As she strayed among the hemlocks, the song started again, but this time she knew it was not a bird.
She danced, he sang, hours together, until she stopped.
‘Luthien!’ he sobbed, ‘Tinuviel!’
‘Not I,’ answered Arwen.’But you, you are Daeron. Go now! Be free…’

Chapter End Notes

The title is adapted from Aragorn's song about Luthien and Beren.
It was Daeron who piped for Luthien as she danced in Doriath and who later betrayed her confidence and went wandering, lamenting her loss.