And by not easy, I mean that no one really even explicitly says it until half way through the last book. You can certainly piece it together before hand, but Erikson has a sadistic way of hiding the ball. Some disagree, but yes, there is one story arc over the entire 10-book series if you ask me. For those who want to discuss it in a different thread, I'm down.

It's not obvious, and you often think it is something else entirely, and most of the characters working towards that goal don't even know they're doing it. That's part what makes it so enjoyable.