Gr 4-8-This well-written and thoughtfully designed series features engrossing topics, some of which have potential as curriculum tie-ins: a "Great Pyramid Mystery" spread in Ancient Mysteries, for example, discusses the history of the massive structures in Egypt and how nobody knows how they were built, and Disappearances outlines the questions surrounding the Roanoke colony. Pages are designed to resemble top-secret files, with some photographs and captions made to appear as though they are taped to the pages. The author takes the same methodical approach to each chapter, presenting the origin of each story and in what manner it has been refuted or proved a hoax, or states that it remains unexplained. Each chapter concludes with a few questions that test readers' memory and comprehension: "How tall is the Yeti believed to be?" (Strange Animals). Though the pages are profusely illustrated with large, well-reproduced photographs and drawings, the layout is not cluttered. This series just might inspire kids to seek out more in-depth materials. (c) Copyright 2011. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.