Inside this 240-page hardback book, you'll find:

- The Years of Darkness and Blood 

- Campaigns of The Age of Darkness: The Siege of Cthonia 

- Age of Darkness: Core Missions – Five new Core Missions, balanced for both campaign games and Matched Play events. 

- Siege of Cthonia: Apex Missions – Two new Apex Missions, with extensive special rules intended for campaigns and narrative games. 

- Age of Darkness: Zone Mortalis 

- Zone Mortalis: Core Missions – Three new Core Missions and two new Apex Missions for Zone Mortalis games, plus specific rules for Cthonian Underworld Zone Mortalis terrain such as Subterranean Tunnels and Promethium Condenser Tanks.

- Legiones Astartes: Rules Addenda :
– Legiones Astartes: Imperial Fists 
– Legiones Astartes: Sons of Horus 
– Legiones Astartes: Legiones Decurion 
– Agents of the Cults Abominatio 
– Legiones Astartes: Inductii 

- Showcase 

In order to use the contents of this book, you will require the Warhammer: The Horus Heresy – The Age of Darkness Rulebook and one of the Army Books for Warhammer: The Horus Heresy.