|“||I read your letter. About the woman you love. I believe you. And I believe in peace.||”|
The Queens, including Demetra, are contacted several times by Rhysand who asks for their half of the Book of Breathings so it can be used against the King of Hybern. They agree to meet with Rhysand and his Inner Circle, and so the Queens winnow to the Archeron Estate. Demetra meets Feyre Archeron and the rest of the Inner Circle, however the queens refuse to give up their half of the Book of Breathings, and leave the estate.
Some time later, Demetra and the oldest queen meet with the Inner Circle to see proof that Rhys and his circle want peace. Rhys show them Velaris through the Veritas orb. Even with the evidence, the oldest queen refuses to give her half of the book, however Demetra disagrees and leave the book under her chair with a letter. In the letter, she confesses that she wishes for a better world and that the the sixth queen was not ill. After Demetra's betrayal is found out, she is murdered and her body is displayed during the attack on Velaris.
Demetra is young, likely no older than thirty years old. She has curly blonde hair with amber-colored eyes. She also has brown freckled skin. She is often compared to a lion.