https://www.polygon.com/2018/2/1/16960706/rainbow-six-siege-outbreak-event-chimera-ubisoft

Tom Clancy’s Rainbow Six Siege is a tactical shooter that is, for the most part, grounded in realism. But a forthcoming event, titled Outbreak, will apparently give the latest Rainbow Six some sci-fi flavor in the form of ... aliens?

Ubisoft has been teasing out details about Rainbow Six Siege’s third year of content, which includes Operation Chimera, with two new operators who specialize in biological and chemical attacks, and the upcoming Outbreak event. Ubisoft’s early promotion for Outbreak seemed to indicate that the Rainbow Six team might be facing a zombie-like threat, but a new teaser trailer now makes it look like the game’s counter-terrorist operatives will face a threat from outer space.