Earlier tonight at a press event in San Francisco, Valve unveiled a brand new multiplayer (versus) mode to be included in Left 4 Dead 2. Scavenge is the name of the game; and if you thought your L4D experiences were frantic before, well..you had every right to, it’s not like you knew about this yet. Onward to the details!

Scavenge has one team play as the four survivors scrambling to collect gas cans from various spots in a small location in an effort fuel up a generator before a two-minute timer hits zero. There are 16 cans total and 20 seconds are added to the clock for each one that’s successfully retrieved. Think timed, goal-oriented Survival mode with an end point that isn’t necessarily your death–though that’s certainly one of the few conclusions.

That’s where the other team of up to four comes in. In control of Special Infected and backed by relentless zombie hordes, the group must do their best to stop the cans from reaching the goal. Two of the new Specials announced have great advantages in the mode: Spitters can set dropped cans on fire, and Jockeys can leap onto the shoulders of a survivor, directing them away from there intended destination.

That’s basically it! Best two-of-of-three with half time’s where teams switch sides. Valve has confirmed that all six L4D2 campaigns have their own unique Scavenge map, nice.

Left 4 Dead 2 will hit shelves PC and Xbox 360 November 17, and it sounds like it’ll be packing a helluva lot more content than the first game offered upon release.