Mrs. Whitney had better stick to her last. She does much better in her established field of books for older girls. This is a mechanical, run-of-the-mill mystery, technically smooth, but leaving the reader with little sense of excitement. It starts in orthodox fashion with Taffy, aged 12, and her mother setting off for Mackinac Island for a summer, where the mother is to run a summer hotel inherited from an eccentric Aunt. The characters that gather to block her project have a hollow, unconvincing quality, despite their obvious choice as exciting, mysterious types. At the end, the loose ends are neatly gathered up, but meantime the reader feels cheated not only in the progress of the amateur detective work but in the answer to the mystery. It's slick, and the author pulls the right stops, but somehow it doesn't come off.