"The White Witch?" said Edmund; "who's she?"
"She is a perfectly terrible person," said Lucy. "She calls herself the Queen of Narnia thought she has no right to be queen at all, and all the Fauns and Dryands and Naiads and Dwarfs and Animals—at least all the good ones—simply hate her. And she can turn people into stone and do all kinds of horrible things. And she has made a magic so that it is always winter in Narnia—always winter, but it never gets to Christmas. And she drives about on a sledge, drawn by reindeer, with her wand in her hand and a crown on her head."
Edmund was already feeling uncomfortable from having eaten too many sweets, and when he heard that the Lady he had made friends with was a dangerous witch he felt even more uncomfortable. But he still wanted to taste that Turkish Delight more than he wanted anything else.
This quotation comes at the end of Chapter 4, during Edmund's first visit to Narnia. Edmund finally finds Lucy after first encountering the Witch and eating Turkish Delight. This passage represents the moment when Edmund chooses the Witch's side, instead of the good side. Throughout the rest of the book, Edmund tries to rationalize his belief in the Witch, he deceives himself and ignores all the stories that portray the Witch as evil. He thinks to himself that the Witch was kind to him, instead of trusting his siblings or Aslan This quotation shows that Edmund has full knowledge of the situation and exercises free will. Edmund does not suspect Lucy of lying to him and accepts what she tells him as the truth. Edmund thinks about his greed and then consciously rejects the idea that the Witch is a dangerous foe. This passage crystallizes the moment that Edmund willfully decides to side with the Witch, and shows that his later excuses are just that—excuses.