Since no one seems to have answered this:

From what we know of Mummy: The Curse, you play as either one of the periodically-reviving nobility of the pre-Egyptian Nameless Empire of Irem (Irem was the capital, by the way), or a member of the cults they set up during periods of activity. Uniquely, Mummies start at Power Stat 10, and slowly lose dots as the Sekhem (essentially non-Supernal magic, its older than that) that keeps the Arisen awake runs out until they hit zero and go back to sleep again. There's also a group of hunters who want that Sekhem, mysterious monsters who aren't pleased with the Arisen cheating death over and over again, and the fact that Mummy morality is exactly what you'd expect from entitled noblemen from an age where "death by barbarian" was a quite real possibility.