Gr 6-9-Jack Landon, 12, and his younger sister, Ashley, who appeared in three previous adventures, are about to leave for Mesa Verde National Park with their veterinarian mom and photographer dad when the family is called upon to accept a foster child, 13-year-old Lucky, on an emergency basis. Mrs. Landon has been called as a consultant to the area because a cougar has attacked a hiker. Ashley is thrilled, but Jack is not pleased to have a last-minute intruder on the family's trip. His attitude changes as he finds himself attracted to Lucky, but she refuses to answer any questions, won't tell anyone her last name, and makes statements that strain credibility. Ashley is quicker than Jack to catch on to some of the inconsistencies in the girl's behavior, partly because he does not want to believe that his sister is correct. Lucky's actions eventually lead all three youngsters into a life-threatening situation involving the cougar. Once they are rescued, Lucky escapes the family's custody and flees the country with her less-than-honest father. The well-developed plot moves right along, and the characters have definite personalities. Descriptions of actual places, their history, and the environment add to the ambience. A solid adventure story enhanced by an interesting study of honesty vs. deception.-Eldon Younce, Harper Elementary School, KS Copyright 1999 Cahners Business Information.