Bayek of Siwa and a dead son — Origins begins at the end of something, in grief so recent that the wound is still open, and Bayek moving through ancient Egypt as the last Medjay is the game's account of what a man does when the institutional role that gave his life meaning has been stripped of its purpose by the death of the thing he was protecting. He finds the truth because finding it is the only forward motion available to someone whose grief cannot be processed until the accounting is complete.

The truth is the Order of the Ancients — the proto-Templar organization whose manipulation of Egypt produced the circumstances that took Khemu. The game is origin in both senses: the origin of the Assassin Brotherhood and the origin of the specific motivation that would eventually produce an organization. Bayek is not trying to found anything. He is trying to close a wound. What he builds is a consequence.