THE MYSTERIOUS MR. MOON Anne Stephenson Markham (Ont.), Overlea House, 1989. 128pp, paper, ISBN 0-7172-2585-2 (cloth) $15.95, 0-7172-2586-0 (paper) $4.95. Grades 4 to 5/Ages 9 to 10 Reviewed by Andre Gagnon. Volume 17 Number 5 1989 September A guest at the Coach House Inn has Peter and Allison so intrigued that, with the help of their friends, they start spying on him. Although they have been told by their parents not to bother guests, they soon gather enough proof to suspect Mr. Moon of wanting to kill Mrs. Gruge, the former owner of the inn. Full of confidence, they plan to catch Mr. Moon in the act on his last evening at the inn. To their amaze­ment, however, they find out that their secretive guest is a well-known murder-mystery writer who is in town to research his new book. The plot of this mystery novel is stretched thin. That children can gain access to the computer file of the police department so easily is not credible. Some episodes, such as the new busi­ness planned by Mr. Moon, are not always fully developed. Others, like the episode at the bank, seem to have been added only to thicken the plot. Emphasis here is not on character de­velopment but on action. A forgettable story that fans of the Hardy Boys or Nancy Drew will swallow up in one rainy afternoon when there is nothing else to do. Andre Gagnon, Regina Public Library, Regina, Sask.