In a Universe called Warhammer 40,000, genetically modified humans called "Space Marines" is an army created by the Emperor to conquer the galaxy and save mankind. Demigods called Primarchs, lead the Space Marines in a quest to reunite the World of Man. Primarchs were scattered to different worlds and become heroes in their own planet. As a Space Marine, players defeat the army of Orks to discover what's been kept secret for a long time.