Did the Russian Grand Duchess Anastasia survive the slaughter of her family, and did Amelia Earhart perhaps survive her famous flight across the Pacific? Where did the evangelist Aimee Semple McPherson go when she vanished in May of 1926, and where did the mystery writer Agatha Christie disappear to later that same year? Was Napoleon in fact murdered, and might the same fate have befallen Dag Hammarskjold? Where's all the loot from the Great Train Robbery, not to mention all the spoils that were stashed away by the notorious gangster Dutch Schultz? Did two other mountain climbers reach the summit of Mount Everest before Sir Edmund Hillary, and did a French airplane cross the Atlantic just before Charles Lindbergh's Spirit of St. Louis? Who was Jack the Ripper, and who was the Axman of New Orleans? All of these questions will be asked anew (and some of them will finally be answered) in the pages of this intoxicating new LIFE book. Here are no fewer than 50 cases from the files, each more baffling than the last. The famous folks are here — from Edgar Allan Poe to Jim Morrison to JonBenet Ramsey — as are equally compelling stories involving people who you have yet to meet. LIFE's editors have unearthed more than a few obscurities for your entertainment. Entertainment? Indeed. As these editors point out in their introductions: "There is something in human nature that draws up to the mysterious. We seek conclusions — but not really. We want answers but are entertained when they prove elusive. A mystery fascinates us, intrigues us, beguiles us. In its uncertainty, it has a softness and a sense of wonder that a solved, buttoned-down case lacks. An unsolved mystery can be romantic." Enter, then, into the romance of The Greatest Unsolved Mysteries of All Time. Puzzle out the possible solutions to these narratives and delight in the extraordinary photographs. Riveting stories and great photography: just what you would expect from LIFE, and the only aspect of this book that is not at all mysterious.