Two years have passed since Susan, Brian and Jim solved a baffling mystery inSan Francisco. This time they have to solve a million dollar mystery: MarkTwain’s secret diary has just been discovered and publishers all over theworld want to get their hands on it… but it suddenly disappears without aclue! Susan, Brian and Jim are determined to find it. Dossiers: Mark Twain in the Gold Country San Francisco and the Gold Rush Alcatraz Island