Valve has made available this morning the second part of four chapters of the comic Left 4 Dead, which examines the history of the original Survivor and acts as a link to the DLC coming out in October called "The Sacrifice", explaining the cause of death of Bill . You can read the new chapter of comics at this address in English and this time focused on the method of transmitting the virus that turns humans zombies and Zoey drama that has lived before joining the other survivors.