XCOM: Enemy Unknown is quickly becoming one of this gaming season's biggest surprises, a genuine twist on the classic series with real-time action and a whole lot of strategy to soak in.  And now it's about to get even bigger, as 2K Games has announced an expansion for the game that'll be arriving next week.

Titled "Slingshot", this new pack will sell for $6.99 (560 Microsoft points) and include three new maps that you can take on through Council missions, as well as a new playable squad member with their own unique voice and storyline.  In addition, various character customization options will also open up, letting you fine tune your team even further – when you're not saving the world, that is.

The pack will release on December 4th across the board, including Xbox Live, PlayStation Network and PC/Steam, so you won't have any trouble gaining access to it and going to town on an alien invasion.  We'll see you on the battlefield.

XCOM: Enemy Unknown is available in stores now.