Many sagas tell of Leman Russ, the Lord of Winter and War, the most formidable of the primarchs - the sons of the Emperor. At the height of the Great Crusade, the Space Wolves attempt to bring the rebellious planet Dulan to Compliance. Enraged by the insubordination of the tyrant Darath, Russ vows to personally execute the ruler, but Lev El'Jonson, brother of Leman and lord of the Dark Angels, advises him to act more cautiously. Darath's forces now face two legions of Astartes, but tensions are rising between the allies, and the rivalry between the Wolf and the Lion threatens to overwhelm everyone.