While searching for the Eye of Ra in the catacombs of Ra's pyramid on Abydos, SG-1 discovered a sealed secret chamber filled with artifacts. Among them was a stone tablet inscribed in one of the oldest dialects of the Ancients. As an ascended being, Daniel was able to translate the inscription which revealed that the Ancients had evolved from a race of humans that had lived long before us, but they had been wiped out by a plague that was sweeping across the galaxy. Those who learned how to ascend became the energy beings known as the Others, and the rest had died out. The tablet also spoke of a Lost City of the Ancients which holds powerful Ancient technology and weapons capable of defending Earth against the Goa'uld. The tablet was brought back to Earth where Daniel and Jonas struggled to interpret the Ancient text and unlock the mystery of the location of the fabled Lost City.

Cross Reference: Ancients, Lost City, Vis Uban

Episode Reference: Full Circle, Fallen