This is a beautifully produced book, with attractive hard cover, good quality paper, very readable layout and many fine illustrations. Every 'mystery' is presented in easily-digestible form, over two or three pages. It would make a good present for anyone with a mild, and fairly superficial interest in the subject.
Unfortunately, the content leaves much to be desired - as I suppose would any volume with 'complete' and 'thrilling' in its title. Despite the publication data of 2007, there is very little twenty-first century information about new mysteries or follow-ups of those that occurred within the last hundred years. The majority seems to be merely a re-statement of articles from earlier publications, and the authors often take a rather credulous view. Their tendency to pay lip-service to sceptics, followed by a nod and a wink implying "we know better, don't we, reader?" becomes rather wearing. There is also a failure to take into account many modern theories and newly-emerging facts which contradict supernatural explanations, often leaving the dubious impression that solutions will never be found.
This is not the book for a reader who would like to make up his or her own mind, based upon objective and comprehensive evidence. As a coffee-table book, however, it is probably worth its cover price for the illustrations alone.