The "darkest chapter" of the Dead Space series is now available on Xbox Live Marketplace in the form of the Awakened DLC for Dead Space 3. The DLC costs 800 Microsoft points.
According to the game details description, "Left for dead on Tau Volantis, Isaac Clarke and John Carver face a daunting journey. As madness takes hold, they find they can't trust their eyes or each other. The trek leads to the ship Terra Nova, now home to a sadistic cult of Unitologists."
Gamers interested in purchasing the DLC can visit the Marketplace blade on their 360 or queue it via Xbox.com here.