Episodes 1-4 are the main story 5-8 came out as a DLC, if I remember.
The game starts with Jesse and their friends excited for a building contest with a cool prize, and they meet a former member of the Order Of The Stone! A scorned member realizes a monster that gets out of control and consumes the entire town; it's up to Jesse and their friends to save the world
Episodes 5-8 follow Jesse and their friends' adventures as the new Order of the Stone. After finding a city in the sky and going through the exit portal, they find themselves in a room full of portals and don't know which one takes them home.