The talented coauthors of Max and Me and the Time Machine return, this time with a tale about the battle of the sexes, as amusing as it is predictable. Scott Wilson and his best friend, Pat MacKenzie, about 12, are ready for macho adventures during their weeklong camping trip alone on Turtle Island--even though their tent is a Hansel and Gretel Gingerbread House deluxe model, with a cookie for a door. knob, that Scott is field-testing for his uncle. They are thoroughly disgusted, therefore, when they discover the presence of females, especially when the discovery occurs as the invaders photograph Scott and Pat capsizing their canoe. What follows is a classic series of pranks and revenges, eventually including the aunt of one of the girls and Cornelius Callihan, a mystery writer who has a treehouse on the by-now rather crowded island. The outcome, in which everyone is reconciled (especially Cornelius and Aunt Katherine), is hardly a surprise, but getting there is all the fun. Greet and Ruddick tell their tale in brisk, witty prose, allowing Scott, their narrator, plenty of wry quips. Though the characters are hardly memorable, they are funny and well-drawn. The result is enjoyable light reading for grade-school children, male and female.