Another installment in the series that brought readers The Pizza Monster and The Princess of the Fillmore Street School (both Delacorte, 1989) . Olivia has been asked to keep a secret from her friend, Desiree--that Desiree's surprise birthday present is a canary. However, Desiree has hired E. J. to uncover the surprise. The story structure is reminiscent of episodes in Sharmat's "Nate the Great" books (Coward)--short, simple sentences packed with humor and a not-too-mysterious plot. The dialogue and Olivia's Maxwell Smart-like comments are more sophisticated, however, and will appeal to readers in between "Nate" and David Adler's "Fourth Floor Twins" (Viking). Line drawings in a comic style adorn nearly every page, capsules of the fun taking place in the text. Although the plot is basic and the characterizations simplistic, this book should prove popular where early mysteries are in demand. --Nancy Menaldi-Scanlan, Wheeler School, Providence, RI Copyright 1990 Reed Business Information, Inc.