For the start of its third year and new season, Ubisoft's Tom Clancy's Rainbow Six Siege is launching a completely new game mode that subverts the expectations of anyone who has been following the game.

Rainbow Six Siege's main focus has lied in its tactical shooter theme with players playing as special operators possessing unique abilities and gadgets. Now the operators on team Rainbow have a completely new mission: fight against the "Outbreak" of an infected zombie-like horde.

Operation Outbreak lets players team up in groups of three to battle the mysterious new enemy. In the first of a series of three trailers released, we can see a space capsule of Russian origin that supposedly crash landed with a dangerous infection. This infection, when spread to humans, creates dangerous creatures in the form of five different "infected hostile" types, which have been outlined on Ubisoft's blog. The types range from standard "grunts" to massive, wall-tearing "smashers." "Apex" will truly put teams to the test with their ability to command other infected and blind players.

Credit: Ubisoft's Blog

It looks like there will be more to the new Outbreak mode than just running and gunning with zombies, though. It seems like the developers wanted to return to the traditional "Tom Clancy" formula that focuses on realistic tactical stealth. Players will have the option to go in explosively, or take their time and work in the shadows. The event also features three separate levels, all of which are linear and "feature a clear sense of progression."

On top of that, two new characters will be introduced that can be used for Outbreak, as well as a limited list of the current operators that we know and love. A slew of new cosmetic DLC will be available as well.

The best part is the packs that get you your new gear is the only thing you'll have to pay for (and are totally not required). The maps, the characters, and the new mode will all be free, as is a tradition with Siege.

Operation Outbreak will officially launch across all platforms on March 6 and will end on April 3. Check out the trailer for Outbreak below and the blog post here for more details.

Rainbow Six Siege is available for PC, PS4, and Xbox, and can be purchased from Amazon here.