Valve has recently launched the first part of its four part free online comic book for The Sacrifice, the prequel story that tells what happens before the events of the upcoming DLC for Valve's zombie shooter Left 4 Dead.
Look for the other three chapters of The Sacrifice to be released over the next three Tuesdays. The actual DLC will be released on October 5 for both Left 4 Dead and Left 4 Dead 2 for both the PC and Mac. Click the image below to check out the first part of this comic series.