Here are some concepts referred to in this trailer for Dreamfall Chapters: 1) The Undreaming, 2) The Storytime, 3) The Thief of Dreams. Not the most accessible of introductions to the series then, but one that should nevertheless whet fans' appetites for the release of Book Two: Rebels.
Dreamfall Chapters is the follow up to Dreamfall: The Longest Journey, which was itself a follow up to The Longest Journey. According to the trailer, the second release in this new episodic adventure is "coming soon".
Previously, Richard Cobbett wrote about the success of Chapters' cyberpunk world (opens in new tab), as part of his Critical Paths series.