It's in around 2000 BCE, they're going to be able to figure out how to navigate that Nile River for transportational purposes. It's pretty easy going from the south to the north because the river goes that way. But once they figure out sails, which Mesopotamia is going to invent, they're going to be able to navigate the river using the trade winds, which flow from the north to the south. And then eventually they're going to be able to trade with internal Africa as they look for supplies to build their most awesome pyramids. They're going to need limestone, they're going to need gold, they're going to need ivory, they're going to need things they don't have, which they're going to have to get. So geography is really important, make sure that you look at that map one more time and you get the big idea that the Nile is the heartbeat of Egypt as we now take a look at the old kingdom of ancient Egyptian society. Are you ready to unify?