In the aftermath of the Isstvan V massacre, a group of Salamanders survivors lay a trap for their foes, a group of unwary Night Lords on the hunt for easy prey. As they lure the Night Haunter's murderous sons into a trap, the battered survivors of the Dropsite Massacre contemplate their fate...and for some of them, it may come sooner than they think.

On an Imperial outpost world on the fringes of tau space, the renowned Commissar Ciaphas Cain and his fractious regiment of Valhallan Guard, newly created from the remnants of two devastated units, find themselves in the middle of a war. As the Astra Militarum struggle to contain worldwide civil insurrection, can the wily Commissar Cain identify the real villain before the planet is lost to the Imperium forever?

'The Dark King' by Graham McNeill. The acts of terror and warmongering by Konrad Curze, Primarch of the Night Lords Legion, have earned the ire of his brother primarch, Rogal Dorn. Wracked by terrible visions of the future, Curze is driven insane and attacks Dorn, setting the Night Lord on an inexorable course towards eternal damnation. 'The Lightning Tower' by Dan Abnett. Rogal Dorn, Primarch of the Imperial Fists Legion, faces a stark reality - he must tear down the magnificence of the Emperor's Palace.

After seven years of bitter war, the end has come at last for the conflict known infamously as the Horus Heresy. Terra now lies within the Warmaster’s sights, the Throneworld and the seat of his father’s rule. Horus’ desire is nothing less than the death of the Emperor of Mankind and the utter subjugation of the Imperium. He has become the ascendant vessel of Chaos and amassed a terrible army with which to enact his will and vengeance. But the way to the Throne will be hard as the primarch Rogal Dorn, the Praetorian and protector of Terra, marshals the defences.

The successor Chapters of the Space Marines number in the hundreds, founded to fight for the survival of the Imperium. Across 13 short stories by 10 different authors, discover the history, customs and stories of 12 different successor Chapters, from famed warriors to unsung heroes.