Yoko and her adopted daughter Morning Dew are on their way to China when the man sitting next to them on the plane collapses shortly after telling them that 'the Seventh Tooth of the Dragon hides a treasure'. Having consulted a local historian, they learn that the Tooth is a mountain, and the 'treasure' is in fact the tomb of an emperor's wife who died in the 11th century, aged six. A sad tale that will soon have Yoko and Dew travelling to the past once more!