LEIPZIG, Germany--Considering that Ubisoft acquired the rights to Crytek's Far Cry and subsequently pumped out a slew of middling console ports and quasi-sequels, we were inclined to write off the original island hop's first true sequel, Far Cry 2, as another quick cash-in. Boy, were we wrong. A core technology team at Ubi's acclaimed Montreal studio has been working on the game in secret for over two years now, and even though it's still weeks away from even entering alpha stage, the hands-off demo of this PC-only title that we saw today at Games Convention went so far beyond the design of the original Far Cry that we don't even know where to begin talking about it.

Far Cry's action moves to the African savannah--and there's a whole lot more to it this time around.

We'll start with the storyline, which doesn't seem to be connected to the first game at all. This time around, you'll choose one of around a dozen mercenaries and undertake a mission to assassinate an arms trafficker known only as the Jackal. This arrogant scumdog is supplying two African warlords with the weapons that are keeping their conflict raging--and tearing their beleaguered nation apart in the process. As the game opens, you'll awaken in your hotel room stricken with malaria, with the Jackal sitting across the room and saying words to the effect that you're so pathetically incapable, he won't even bother to shoot you. But he'll leave a pistol by your bedside before he leaves, just in case your sickness gets too bad. Your goal will be to use that gun--or any other destructive means you can employ--to take out the Jackal, and what you do between that opening scene and the eventual completion of your mission will be up to you.

Put simply, Far Cry 2 is the closest game we've seen yet to a true "open world," and that's not just because you can roam around the entire game without ever seeing a loading screen. The only plot and environmental elements that are set in stone--the story's "superstructure," as creative director Clint Hocking puts it--are those described in the previous paragraph. Everything else is mutable, based on your actions, allegiances, and chosen missions, and ultimately the cascading effects of all those choices you make. Both warlords have a command hierarchy of captains and lieutenants, and if you happen to kill one of those underlings, the guys below him will move up to fill the role. You can even take out one of those warlords, and his number-two guy will simply become the new warlord. But it will be up to you whether you take missions from or against those two factions, ally yourself with them, try to take them down, or play them both against the middle. The game will even populate its world with the other selectable characters you didn't choose, and they'll act as agents who are also working in Africa, whom you can befriend and count on in a tight spot. We'll give more info on that later.

Weather patterns, foliage, and even fire will obey the laws of physics.

The organic nature of Far Cry 2's world doesn't stop at its residents; practically everything we saw during the demo was dynamic and realistic, thanks to the new engine Ubi Montreal has built from the ground up for the game. The game simulates full weather patterns and air currents, so when you see clouds in the sky, they aren't there because an artist painted them on the skybox--they're there because the atmospheric conditions were right for clouds to form. The same goes for falling rain and howling wind, the latter of which will realistically blow tree branches, grass, smoke from fires, and dust from the ground in the same direction it's moving. Those trees can be broken apart, and that grass can be flattened by a passing jeep--and they can both catch fire from any incendiary source, by the way. Heck, we saw a grassy field catch fire from an exploded fuel canister, and the fire actually began to spread in a particular direction simply because the wind was blowing it that way. Hopefully this cyclical example gives an impression of the sorts of dynamic systems at work in Far Cry 2.

As for our demo itself, we saw a brief section of the game where the player had taken a mission requiring him to attack and destroy a fuel depot. This began in a dense, oppressive jungle like those from the original Far Cry, but Hocking commented that the demo began in this area only to show that there will be jungles like those of the first game. The player then moved out into the open to show us a vast, open savannah, the likes of which will apparently make up most of the game's world. That world will apparently be huge; the player raised a paper map (much like a treasure map) and a functional compass to his perspective, and we were told that map showed about one kilometer of terrain, and that this represents just under one percent of the gameworld's total size. Again, you'll be able to roam around that entire world while it streams from the hard drive, without ever seeing a loading screen.

The game's free-form artificial intelligence means there's no telling what your enemies are doing down there.

When the player approached a mercenary camp and spied on it with the sniper rifle's scope, we saw a number of guards milling around. One was eating a meal in a hut, two were patrolling around the premises, and so on. Hocking commented that none of these actions are in any way prescripted. That guy won't always be eating in that hut--sometimes he'll be out on patrol, or he might be up in a guard tower, or any number of other actions. The bottom line is, if the game works as designed, you'll never find the exact same situation in the same place twice. In every mission, you'll have to hit the ground running and decide what to do on the fly.