It starts out with a civilization 1000 years more advanced than we are. An ancap society that is more educated, intelligent, enlightened, prosperous, beautiful and happy than anything we have ever seen. Then the thought leaders at the time decide that they wanted to implement "true socialism". While pursuing this "utopia" the society destroys itself at every level, and rips itself to shreds.
By time it's all over, all that's left behind is a bunch of primitive hunter gatherers that we know of today as historical Africa.