The Purple Sapphire

It was a stone of wisdom and prophecy. For twelve years, the British Secret Service ransacked India for General Wedderburn's kidnapped daughter, Evelyn. They found not one trace of her. The General's search eventually led him to the Himalayas, where he found Captain Joicey, hospitalized, delirious, and badly burned. Joicey held the final clue to his daughter's whereabouts—a mysterious lead box inscribed in an ancient language with a huge purple sapphire inside. Armed with this new knowledge, Wedderburn then enlisted the help of an adventurer and his niece for the final leg in his never-ending quest. So to the rim of Earth's last frontier they ventured, searching for a long lost girl and holding the sole key to a long forgotten civilization—a civilization that once knew more about science than any scholar in the modern world.