Swamp Fever only has four levels, while most L4D and L4D2 campaigns have five levels. This means that you get to have fun wading through waist deep water, battling it out in rickety shantytowns, and making an epic last stand at a giant plantation house in order to escape by boat. While the inhabitants attempted to fortify the enclave to keep the zombie horde out (as well as the government and any outsiders), the defense failed and the place is overrun as the survivors arrive. In Swamp Fever, the four survivors come upon a small enclave hidden deep in the bayou. So read on for plenty of new details, including info on the new special zombie being revealed and more.

We also got to play through the entire campaign, whereas only the first two levels are playable at Comic-Con. We were up at the company recently to get one of the very first looks at Swamp Fever, the new campaign that Valve is revealing at the show. Valve is going to be at Comic-Con later this week in order to give the first public hands-on of Left 4 Dead 2, but if you can't make it to San Diego we've got all the details of what Valve's showing, and more.