THE MAD HACKER. Brown, Susan and Anne Stephenson. Richmond Hill (Ont.). Scholastic-TAB, 1987. 128pp, paper. $3.95, ISBN 0-590-71388-4. (An Ash Grove Mystery). CIP Grades 5 to 8 Reviewed by R. Rennie Volume 16 Number 4 1988 July If two grade 7 girls solve a mystery, they will help their two friends and perhaps get an A on their computer science project. A special new computer has been installed in Ash Grove Junior High (even though the book cover says this is an "Ash Grove High Mystery"). Liz and Amber are trying to get access in order to finish a computer whodunit, but many mysterious things are happening and their friends Craig and Jonathan are in trouble. By being in the right place at the right time, the girls get clued in to who is doing what. The book is fast paced and has a definite junior high atmosphere. The characters are believable young people dashing from crisis to crisis with occasional lapses into thought. R. Rennie, Daniel Mclntyre Collegiate Institute, Winnipeg, Man.