Game developer Monolith Productions is bringing a unique endgame mission to the upcoming "Middle-Earth: Shadow of War" which will see players on the defensive as well as repelling progressively harder counterattacks from their enemies. Completing the task will unlock the game's true ending.

The mission, called "Shadow Wars," is a mini campaign in itself and will take place after the game's story has been concluded and after the player has successfully conquered all of Mordor. The game will take the fortress assault, which is a large part of the gameplay, and swap the sides. This means that the player is tasked to hold the forts while Sauron and his armies launch their counterattacks.

These attacks are split into different stages, with the difficulty increasing with every attack fought off. Whenever a fortress is defended against the enemies and held until all-attacking warchiefs have been defeated, the players will keep that fortress.

Should players fail to hold a fort, and is overrun by the attacking horde, Sauron will be able to recapture the fortress and put it under his control. Players would then need to launch their own offensive to retake the fortress in order to advance to the next stage.

Aside from this, players may also need to embark on a rescue mission to save one of the orc followers that was manning the fortress as the overlord.

After successfully completing all the stages in "Shadow Wars" players will be able to view the true ending of the game, which would reportedly tie "Shadow of War" to the plot of "The Lord of the Rings." No further information is known about this tie up, so players will need to wait for the game's release in the fall in order to see how "Shadow of War" will conclude.

"Middle-Earth: Shadow of War" is slated for a worldwide release on Oct. 10 for Microsoft Windows, PlayStation 4 and Xbox One.