The Horus Heresy spans innumerable desperate battles and bitter grudges – many shrouded in mystery, or the subject of grim and terrible rumours. The champions who fight these far-flung battles are unlike any in the galaxy's history, warriors armed with inimicable strategies and esoteric weaponry, locked into struggles across sprawling arcologies, towering citadels, and claustrophobic tunnels.

In this book, you will find five accounts of battles from the Age of Darkness, along with the campaign and missions rules to recreate them – or similar struggles – on the tabletop in games of Warhammer: The Horus Heresy.

You'll also find new and updated profiles for five notable Legiones Astartes units unique to Legions that fought in these battles – the Night Lords, Iron Warriors, World Eaters, Ultramarines, and Salamanders – as well as expanded rules for the Emperor's Children Traitor Legion, and complete rules for their ascended Daemon Primarch, Fulgrim Transfigured.

Inside this 112-page hardback book you'll find:

– The Defence of Sotha – In a storm-wracked system, ragged Night Lords prey on an Ultramarines garrison. Includes background lore and an Age of Darkness mission inspired by the final assault. Plus, rules and a conversion guide for Night Lords Atramentar Squads – murderous Terminators sworn to Sevatar.

– The Siege of Hydra Cordatus – Battle-hungry Iron Warriors assault an Imperial Fists citadel. Includes background lore, an Age of Darkness mission and a Zone Mortalis mission themed around the siege, and Exemplary Campaign rules for tying both missions together. Plus, rules and a conversion guide for the Iron Warriors Dominator Cohort – Perturabo's forsaken Terminator bodyguard.

– The Battle of Armatura – A war-world of Ultramar comes under attack by a World Eaters armada. Includes background lore, three Age of Darkness missions based on the invasion, and Exemplary Campaign rules for tying all three missions together. Plus, rules and a conversion guide for World Eaters Red Hand Destroyer Assault Squads – planet-scouring berserk warriors.

– The Battle of Calth – Entrenched Ultramarines wage underground war against Word Bearers and their daemonic allies. Includes background lore, three Zone Mortalis missions, and Exemplary Campaign rules for tying all three missions together, with a unique Daemon unit exclusive to the campaign. Plus, rules and a conversion guide for Ultramarines Nemesis Destroyer Squads – marksmen armed with specialist bolters.

– The Purging of the Invocastus Sector – Vengeful Salamanders strike at a world conquered by the Emperor's Children Includes background lore and an Age of Darkness mission themed around bloody ambushes. Plus, rules and a conversion guide for Salamanders Sanctifier Squads – elite close-range weapons teams.

– Daemon Primarchs – Rules for using Fulgrim Transfigured, the Primarch of the III Legion in his daemonic form. Plus, Legiones Hereticus rules to represent his Legion, the Emperor's Children, in an even deeper state of corruption.