Alpine Creek

Alpine Creek is the first chapter in the customised Cold Stream campaign which was subsequently released in beta format as a DLC offering in April 2011.

The chapter opens with a reversed cut scene showing players the route to be followed. Players begin by standing in the bed of a fast-moving stream or creek flowing through a wooded area. In single player, the human player starts equipped with a single Pistol, two AI Bots will have Submachine guns and the third will also have a single Pistol. Health and a melee weapon (usually an Axe) are available under the water next to the starting point. (Note that the human player will not have the usual option of picking up a Pump shotgun or Submachine gun at this stage.) If playing as Nick, Ellis will make a general statement to the group that he learned to use a gun before he learned to walk and, if the human player takes Nick's character, Ellis will follow this up with a jibe about Nick's suit.

Once ready, teams head down the bed of the stream and almost immediately encounter larger than normal infestations of Common Infected and Mud People interspersed with Special Infected (chiefly Chargers, Spitters, Jockeys and the occasional Smoker). Since the Submachine gunners represent the core of the team's firepower, but they are AI Bots it is a good idea for a human player to let them take down the heavier opposition. Once under way and the first enemies are encountered, Rochelle and Nick will begin to recycle on a repetitive basis the lines they used in Swamp Fever concerning mud and Mud People.

After a short distance, the creek bed opens out. Teams should climb the left bank and proceed forwards until they see the supporting posts of the swing bridge seen earlier in the opening cut scene. After cleaning out the enemies milling around below, teams cross the bridge and enter a two-storied forestry building. This will usually contain minor supplies (e.g. an adrenaline shot) and an Axe. After going up the stairs, teams will look out of the window into an area thickly populated with Common Infected and Mud People who will aggressively respond to the team's presence in the building by swarming forward and climbing up to the window. A Charger is also likely to spawn and do likewise. This combat is relatively easy as all a player has to do is to allow them to approach closely and defend the window as they climb up one behind the other.

Once it is safe to do so, teams drop down from the window (thereby denoting a "non-return" feature in the chapter) and tippy-toe across a fallen tree trunk spanning a deep forest pit. Up ahead is a tunnel entrance barred by some timber which can be shot and smashed down to allow the team to enter. A small swarm of enemies will be found in the sharply inclined tunnel, at the base of which is the safe room for this chapter.

Overall, the fighting in this custom chapter is more intense than is the case in a comparable standard Left 4 Dead 2 equivalent; indeed there are none of the "quiet moments" that are fairly normal in a standard L4D2 chapter. In addition, the team's starting fire power is considerably weaker whilst the numbers and aggression of the enemies encountered are both noticeably enhanced.