The Mirror

From Author Wars - https://authorwars.com/publications/the-mirror-368223.html

Overview:

Title: The Mirror
Author: Marlys Millhiser
Year: 1979
Publisher: Putnam / BCE
Pages: 383
Binding: Hardcover
Type: Novel
Title Reference: The Mirror
Notes: This appears to have a substantially different page count than the true 1st edition (414 pp.). Stated Book Club Edition, code #1852 on back DJ flap, gutter code U10, implying the print date March 1979. Page count is actually 383 pages, as stated on Open Library.