Early in the 21st Century, mankind made an unbelievable discovery - one of enormous scientific and historical significance. Too bad it will lead to the Earth's destruction! Now there's only one hope and his name is Sam "Serious" Stone. Serious Sam has one chance to change the past and save humanity from total extinction. He must journey through ancient Egypt and traverse vast, open desert levels where massive pyramids dot the landscapes, concealing deadly crypts and perilous passages beneath.