I've gone and broken the rules by writing a pair of drabbles, rather than just one, so I'll only post one on the drabble community. I'll post both here, though.
"I will give you gold," she said, and he said no. She offered him kingdoms, but he shook his head. She clad herself only in golden hair, but he just turned his face aside. "I know who you are," Bran murmured. "He warned me."
Her silver eyes darkened. She touched his cheek, and pictures radiated from her touch. He saw Will, always far ahead of him; Will, so magical, when Bran trailed behind. Compared to Will, Bran knew nothing. He was nothing.
"I will make you worthy of him," she whispered, "if you tarry for a while."
Bran succumbed. "Yes," he breathed. "Yes."
When Bran emerged, Will barely even blinked.
Bran glanced at the fading sun. "Only a few hours, then." He grabbed Will's arm. "It was amazing. I was in Fairyland. Really! Now we can walk side by side."
Will said nothing.
Bran's smiled faltered. "You're pleased to see me?"
Over two hundred years, a desperate vigil became just habit. In two hundred years, he had grown used to being alone. "Yes," he said.
A mask of silver fell over Bran's face. "I can see truth and lies now, written in a man's breath."
Changed forever, he walked away. Will felt nothing.
Note on the folklore: One thing all the ballads agree on is that accepting an invitation from the Queen of Fairy is a Bad Idea. She offers you wonders, but, if you go with her, you tend to find yourself chained in an everlasting contract with your soul committed to hell, or other similarly inconvenient things.
Sometimes, you spend a happy time with dancing and drink, and emerge laughing to find that years or centuries have passed, when you thought it but a few days. If you're very lucky, you emerge changed - gifted with soothsaying, or the bardic gift, or some such (though this doesn't really compensate for the fact that everyone you ever knew is now dead). If you're unlucky, you find that you emerge in the body of the 150 year old man you really ought to be, and crumble to dust, which is somewhat depressing.
Really, the lesson here is: Don't talk with Strange Fairies.
I might well end up expanding these drabbles. As I said, I've had the idea for ages. Writing this could well jump-start the idea properly (after I've finished my half-written Dark AU, that is.) I'm eager to know what happened to Bran in Fairyland, and how Will spent his 200 years of waiting. I'm also interested to know how things will work out in the future.