Arienrhod, Moon Dawntreader, and Sparks Dawntreader are three of the more important major characters in The Snow Queen. Moon Dawntreader, Arienrhod's clone, has been raised by her unwitting host-mother, a fisherwoman of the Summer People. As a result, she does not share Arienrhod's love and need for technology. Moon sees herself in the future as the wife of her maternal cousin, Sparks Dawntreader. Moon is a determined young woman who also wants the privileged position of a sibyl, a person who can communicate directly with a higher power when asked the right question.

(The higher power is a computer of some sort). Would-be sibyls must make a pilgrimage to a designated spot where they are mysteriously tested and chosen or rejected. Sibyls travel with impunity throughout Tiamat but are specifically banned from Arienrhod's city of Carbuncle. When Moon and Sparks arrive at the test site, Moon is chosen...