The canyons and mesas of New Mexico provide the setting and the only colorful aspect of a dull mystery about several children on vacation who discover the whereabouts of a lost turquoise mine belonging to a tribe of Indians. When Chip and Karen arrive at the Double-O ranch, they are intrigued by stories of the precious bluestone mine and by the peculiar behavior of Josh Crowe, another guest. Chip's friendship with Pedro, a native of the area, is climaxed by an expedition into the hills where the boys learn of the cattle rustling operation of Josh Crowe. On a private search of her own, Karen stumbles on the lost mine and reaches the boys just after their escape from the rustlers. The treasure is restored to the Blue-Stone Indian tribe and the children are credited with the achievement. Miss Thompson's pedantic approach to her subject reduces suspense to a minimum and her unimaginative development of plot leaves little to interest the reader.