In Rainbow Six Vegas, terrorists have kidnapped a couple of Rainbow operatives and launched an assault on the city of Las Vegas itself. The kidnapping plot actually ties into the story of the Xbox but you'll play as a backup, two-man Rainbow team assisting the main team featured in those versions. As a two-man team, you'll alternate between controlling Brian Armstrong, the assault expert, and Shawn Rivers, the sniper. For instance, you might begin a mission as Brian and come under heavy fire or find a security gate that you can't open, at which point, the game will automatically switch you to Shawn, so you can help Brian.