Points: 1000.
Mission: Crossfire.
Secondary Objectives: Engage On All Fronts, Oaths of Moment and Slay The Warlord.
In the aftermath of the Plague Wars, the Rift Wardens assisted the Ultramarines in cleansing the Paragon system of the Nurgle infestation. Concerns had been raised that the Rift Wardens had been overzealous in their efforts to purge the chaos presence, killing innocent Imperial citizens. Chapter Lorgraine made the case that the only way to ensure that the taint of the ruinous powers was cleansed from Paragon Secundus was to eradicate the population and start again. Despite Ultramarines captain Chrissus requested a hold on the purge Lorgraine continued to decimate the civilian population.
This lead to Chrissus leading an attack on the Rift Wardens attempting to force a stay of execution. Lorgraine saw this as an attack on the chapter and unwarranted, and retaliated with extreme prejudice. The battle was brief and saw the Ultramarines killed to a man, including captain Chrissus. The Ultramarines, seething with anger, mobilised and brought the two chapters to war.