Last time we looked at Rainbow Six Vegas' ambitious single-player story mode, we talked about the development team's efforts to streamline the game experience by stripping out noninteractive cutscenes, bland textual mission briefings, and other antiquated conventions of the realistic shooter genre. Instead, the game will present everything you need to know--mission updates, story progress, and tactical information--dynamically from within the game as you play, and today at Ubisoft's office we got to take control of the game from the very beginning and play the opening levels in Mexico for a solid two hours to see how this will work.

　　Wait, Mexico? What are you doing south of the border in a game about Las Vegas? For one thing, the game needed a training level--but in keeping with the more dynamic nature of the game, you'll get your training after you hit the ground, rather than in a nice, safe test area. At the outset, you'll take control of Vegas' main character, Logan Keller, as you head with fellow Rainbow members Kan Akahashi and Gabe Nowak to a small Mexican border town where suspected terrorist ringleader Irena Morales is holed up, smuggling operatives and weapons into the US. The tangos were relatively few as we made our way through the streets in the initial section of the game and were instructed in mission-relevant scenarios on core gameplay functions like taking cover, rappelling down walls, commanding our teammates, and so on.

　　The intro levels set in Mexico do a good job of introducing the gameplay concepts while you're actually under fire.

　　Though we've played Vegas a good bit before, we still enjoyed this chance to get a feel for the game's finer points straight from the beginning. For instance, we had a chance to experiment with the snake cam, which lets you see under doors and tag enemies for prioritized neutralization. You can have your teammates breach a door with a flashbang, frag grenade, or smoke grenade, or even blow the door itself down with an explosive charge. We were entertained just seeing how well we could set up a room breach to see if we could clear an entire room of tangos without lifting a finger ourselves. This fifth Rainbow Six looks like simultaneously the most complex and most action-packed so far, and we appreciated the learning opportunities this introductory area afforded us.

　　Unlike past games, Vegas won't send you into one discrete map per area and then extract you when you've finished your tidy mission. Instead, once you hit the ground in a particular place (be it a dusty Mexican border town or a posh Strip casino), you can expect to be there for a while. The introductory sequence, in fact, lasted through four distinct levels; we first fought in the arid streets and dilapidated warehouses of the village before heading down a mining shaft to Morales' temporary hideout to capture her and root out her heavily armed minions.

　　This connected feel of the maps in Mexico gave the flow of the game a more natural feel, since the end of one level is simply the beginning of the next, similar to seamless, story-driven shooters like Half-Life. And when we finally left Mexico by helicopter, there was no summary screen showing our kills, or a text briefing on our next objective. Instead we received a radio communication from Rainbow leader Ding Chavez that directed us to an even more critical, developing situation in Las Vegas, so the next mission after the loading screen began with us setting down in that very same helicopter and diving right in to the next mission with barely a chance to take a breath.

　　Ubisoft Montreal is clearly putting Unreal Engine 3 to good use in Vegas.

　　But a lot happened in Mexico before we made it to the extraction point. Without giving too much away, when we finally caught up to Morales in her subterranean lair, she offered us some choice words before pulling a fast one on us that deprived us of our teammates and all of our gear, save one silenced pistol. So the remainder of the Mexico mission became a game of survival, as we crept through the tunnels alone, stealthily picking off guards like Sam Fisher might do, and trying to arm ourselves after taking out the enemies. We found this an interesting way to turn the Rainbow Six gameplay on its head. Without a high-powered, long-range assault rifle and other amenities like night and thermal vision to aid us, we suddenly felt a whole lot more vulnerable while creeping through dark tunnels and factories, and the excitement of our escape was thusly increased.

　　Rainbow Six Vegas' single-player campaign has been looking better every time we've seen it the last few months. The game is making great use of the third-generation Unreal Engine--we were highly impressed at one point to emerge from a warehouse onto a catwalk and see a brilliant sunset over the hillside horizon outside of town, which was seemingly a good couple of miles away. We're looking forward to seeing how the designers map Vegas' core gameplay concepts onto the elaborate casino environments of Sin City, and we'll get to see the entire campaign in its final form when the game ships in just under a month. Also stay tuned for an update on Vegas' multiplayer, including exclusive high-definition footage of several maps and modes in action.