The ox, the horn, and the Sheaf are symbols of tribes belonging to descendants of the biblical patriarch Jacob.
We pick up.
We go back and forth in time and meet (also fictional) archaeologists who find clues as to the adventures of our wandering Israelites.
In her book, Meg theorizes with fictional characters what may have happened to at least two of the lost tribes.
In 723 BCE, Assyria concurred the northern Jewish kingdom of Israel, and at that point, all history of those folks vanished.
The ox, the horn, and the Sheaf are symbols of tribes belonging to descendants of the biblical patriarch Jacob