Get a good look at this video because there's no telling when this might be taken down. It's footage of the closed alpha for Tom Clancy's Rainbow Six Siege. Someone uploaded it to YouTube yesterday.
The video, assuming it's still viewable, depicts a hostage rescue mission aboard an airline, similar to what was seen at E3 2014 when Ubisoft announced Rainbow Six Siege for PlayStation 4, Windows PC and Xbox One.
Update: The video was indeed taken down. A copy of it is below. The original is by Gabriel Krieger.
Last week Ubisoft Montreal started taking signups for a closed alpha for Rainbow Six: Siege, which appears to be the source of this video.
In the video, players demonstrate how they set up mobile cover, flank and fire upon the hostage-takers at the back of a jumbo jet. This is a multiplayer match, not from the game's campaign.
Rainbow Six: Siege took the place of the canceled Rainbow Six: Patriots, which Ubisoft scrapped after it realized it would release too close to the beginning of the new console generation. For more on Rainbow Six: Siege, see Polygon's preview from E3 2014.