There’s a new reason for players to revisit “Left 4 Dead.” Just recently, Turtle Rock Studios co-founder Chris Ashton revealed that a new DLC for the first-person shooter is available for download for free.

“Left 4 Dead 2” was released in July 2013, so it’s been more than three years since it came out. Without any sign that a new installment could be released, many players may have already turned away from the franchise. However, things are going to change this week.

Apparently, Turtle Rocks Studios, the company that originally developed “Left 4 Dead” until Valve took over, released the unfinished campaign for the game. Ashton even took to the Turtle Rock forums to provide the link where players can download the campaign for free, as per GameSpot.

However, players shouldn’t expect a lot from the new DLC, called "Dam It," because Ashton stated that it’s a “gray box” work — in simple terms, unfinished. Fortunately, Ashton did say that it is playable from start to finish.

The new “Left 4 Dead” campaign comes with Survival maps that never shipped with the game. It also ties in two other campaigns, Dead Air and Blood Harvest.

Polygon has learned that the unfinished campaign features a detailed map that serves as a good strategy guide. The video game website also revealed that "Dam It" starts with the player finding his way into an airstrip and ends at a hydroelectric power dam.

Since "Dam It" is an unfinished campaign, players can expect to stumble upon certain issues within the game. An example of these issues is the inability of fire, smoke and explosions to cause panic events in the hangars.

Another issue pertains to how zombies are not crawling in the orchard all the time. Then, when explosions hit the covered bridge, it does not collapse. Finally, wandering fires are missing when the forest area is burning and the farm house mob is not capable of spawning in the far side of the forest, according to GearNuke.

There are two ways to install the “Left 4 Dead” DLC. For automatic installation, one should unzip the downloaded file and double click it to launch. On other other hand, manual installation as an add-on simply requires one to unzip the file and copy its content to the add-ons folder of “Left for Dead.”

More details about Dam It and the file to download and install are found here.