The Maze in the Heart of the Castle

From Author Wars - https://authorwars.com/publications/the-maze-in-the-heart-of-the-castle-228853.html

Overview:

Title: The Maze in the Heart of the Castle
Author: Dorothy Gilman
Year: 1983
ISBN-10: 0385178174
Publisher: Doubleday & Company
Price: $11.95
Pages: 230
Binding: Hardcover
Type: Novel
Title Reference: The Maze in the Heart of the Castle
Notes: Cover artist on back flap of archive.org copy.