I recently blogged at Forbidden Fiction about how my fairy tale retellings usually start with a question--a point of dissatisfaction in the original story. This is true of The Six Swans, too.
In the classic version of the story, the main character must spend seven years silent, sewing shirts for her brothers, in order to break the curse that has turned them into swans. A king's servant discovers her in a tree one day. For some reason, she throws her clothing down to him one article at a time (in the story, this is presented as an attempt at discouragement, but that really doesn't make sense to me). He is stunned by her beauty and takes her to the king, who promptly marries her. The king's mother is evil, for some reason, and takes away the babies the new queen bears, telling the king that his silent wife is responsible for murdering them. The king refuses to believe this for quite some time. Eventually, his mother convinces him that his wife is killing the children, and he agrees to have her burned at the stake. Luckily, this happens to coincide with the end of the seven years, and the girl is able to restore her brothers and explain herself just before she dies by fire.
Now, that is a weird, weird story. What particularly interested me was the king's trust in the main character. She can't speak to him. Her behavior must appear insane. What could he have known or felt about her that would give him the sort of confidence in her that he displays, in the face of damning evidence that she's a murderer.
Trying to answer that question drove my entire writing of the novella. In my version of The Six Swans, the sexual connection between the king and his bride is so strong that his body trusts her even when his mind does not. Trust is visceral and physical.
As is common for me, that hypothesis then spread through the story, affecting how I portrayed both of the main characters.
If you'd like to see how this worked out, you can pick up the book here.