Tasks go in - order, if an | exists it means you can do those in any order, but have to all be done to continue on to the end. If tasks aren't listed in a chain, they can be done at any time.

Expansion Progression Quest Chain: Overcoming the Cataclysm - Not of This World - Answering the Call - The Bixies of War | For the Sake of the Forsaken - The Missing Scroll - Fourth Gate Investigation - Cautious Recruitment
Mission Quest Chain: The Bixies of War - Saving Jacyll
Heroic Adventure Chain: Assault The Main Hive - Jacyll's Jailbreak
Heroic Adventure Chain: The Great Hunt - They've Gone Too Far This Time - They're Everywhere!
Heroic Adventure Chain: Espionage Starts At Home - Always Follow the Money - Working Overtime
Heroic Adventure Chain: Endless War - The Thunder Gun Escape - General Sagrinta's Last Stand
Mission Quest Chain: The Doomscale Horde - The Defense of Lendiniara | Xulous Prime - The Legacy of Bayle | Saving Jacyll | Houses of Thex - Hate Rising | The Fall of Lord Bayle | Burn Out - A Guide Beyond the Rift - The Journey Home