Overwatch is getting a new co-op game mode as part of its next big event, a leaked trailer revealed Monday, which Blizzard then confirmed on Tuesday for its launch. The trailer, originally posted on YouTube by the official PlayStation France account, has since been taken down, but Polygon published the details. The name of the mode has been translated from French as “Insurrection,” although as Polygon commenter Josh Harmon pointed out the English language name will likely be “Uprising,” to match the most recent official Overwatch comic. According to the trailer, the event will run from April 11 to May 1.

It looks like Overwatch‘s Uprising mode will take place on a version of the existing “King’s Row” map set during the daytime. In the trailer, players battled hordes of robotic enemies — hence comparisons with “horde modes” like that found in the Gears of War series — while they “relive one of the key moments in the history of Overwatch,” according to a translation of the video’s description. Blizzard’s formal announcement confirmed that the mission takes place during Tracer’s first mission as a new recruit for the organization.

The trailer only showed the characters Tracer, Reinhardt, Mercy, and Torbjorn. Although it’s not confirmed whether they’ll be the only playable characters in Uprising, that seems likely. Last year’s Halloween event, Junkenstein’s Revenge, featured only four playable characters (Ana, McCree, Hanzo, and Soldier: 76), and the four seen in today’s leaked trailer were all members of the Overwatch team, which seems like it would make sense given that this mode is meant to recreate a “key moment in the history” of the game’s world.

That said, the Uprising/Insurrection event will reportedly also feature new skins for McCree, Genji, Widowmaker, Mercy, Torbjorn, Bastion, and Orisa, plus dozens of new skins, sprays, emotes, and poses.

Overwatch has a vivid and expansive backstory, although that’s not particularly evident simply from playing the game. Blizzard has fleshed the game’s universe out through short animated films and comics, including the one that revealed that Tracer is gay. The average Overwatch player mostly experiences an online shooter with little to no context, though, so it’s nice to see Blizzard possibly incorporating more of the story into the actual game.