We've had to walk on eggshells to avoid spoiling the twists and turns of Left 4 Dead 2's imminent content expansion, "The Passing," due out this Thursday on PC and 360. This post is ... well, it's no different at all. Posted after the jump is the list of Achievements included in the DLC, a handful of which may ruin certain plot points you might want to avoid until you get your hands on the new chapter. You've been warned!