Left 4 Dead's eerie atmosphere was made exponentially more engrossing by the warnings scrawled on the walls of each safe house by other survivors. Left 4 Dead 2's downloadable chapter "The Passing," released earlier today, features the above note, apparently written by another down-on-his-luck Zombocalypse veteran. Located by the sharp-eyed bloggers of Destroyed Controller, It reads: "Otis, Out of film, no helicopter. Zombies are too fast. Not going to make it. - Frank West."