An amateur astronomer on Mars first spots the asteroid falling sunwards, and when its orbit is computed it is called Kali after the goddess of destruction. It is 65 million years since the reign of the giant reptiles ended and now Kali threatens a similar fate for mankind. As captain of the research vessel Goliath, Robert Singh is put in charge of the immense task of pushing an asteroid off course. But even the most meticulous planning cannot anticipate the human factor.