The Sanders-Hardiman expedition, made up of a team of European archaeologists and scientists, is returning from Peru with the mummy of Incan Rascar Capac. No sooner do they arrive home than, one by one, they are struck down by a mysterious illness. A strange clue is discovered near each victim: shards of crystal thought to come from crystal balls. In an attempt to save Professor Tarragon (the last remaining member of the expedition not affected by the illness), Tintin, Haddock and Professor Calculus stay the night at Tarragon’s villa. During the night, the occupants of the house are plagued by nightmares; when Tintin and his friends wake up, they discover Professor Tarragon in a coma with fragments of crystal beside his bed. The next day, Professor Calculus makes an incredible discovery that takes our heroes on a whole new adventure!
