So at the end of the day, this civilization, which is going to last for over 500, 600 years, is going to slowly start to disappear. So why don't we take a look at what made them go away. All right, guys, so all good things must come to an end. That includes the Harappa civilization. Again, they're run about 2500 BCE to about 1750 BCE, a good 750 years, but slowly they're going to be wiped off the map over about a 250 year period, we think, somewhere around 1750 and 1500 BCE. And there are three possibilities. The first possibility is that there was just a giant earthquake, and not only would that kill lots of people, but that could have literally moved the river.