For those longtime fans of Valve’s Left 4 Dead series, the road to seeing a third installment is still a long ways off. That hasn’t stopped the modding community, which has been active in the game for years. The latest achievement is “Chernobyl”, a massive custom campaign that’s taken over nine years to develop, and the first chapter is now available for fans to enjoy.

The story for the campaign picks up with the infection spreading across Europe. The group of survivors you play as are on their way to Siberia, hinging on hope that the permafrost of the region will stop the infected. Their plane will take them there, but they need to pass through Chernobyl. You can see where this is going.

The campaign’s five maps sport tons of new models for you to shoot up (400 new models and 500 new textures, to be exact), as well as custom panic events, and the maps themselves are closely modeled after the actual Jupiter Factory/Pripyat (for you S.T.A.L.K.E.R. fans).

To play the campaign, you can head here to get started. The rest of the “Chernobyl” campaign is expected to be released in the near future. And if you still haven’t snagged L4D2, it’s on an 80% discount thanks to the Steam Winter Sale at the moment, so get it!