Call of Duty: Black Ops

But it's not long before their peace is interrupted by a bit more neck-knifing and some strategically lobbed semtex. As the alarm is raised the scene quickly turns to chaos - the air is thick with bullets, wooden huts explode at a rapid rate and the chickens go mental. Women and children are curiously absent from the scene but there are plenty of grown men to shoot. Our hero takes advantage, blasting away until they've all stopped moving.

Time to move into the tunnels running out of the village and into the jungle. A bloke called Reznov chucks us a torch and we wish he hadn't, seeing as all it just makes it easier to see the scurrying rats, crawling cockroaches and bits of leg lying about the place.

A tense scene follows. A soldier drops suddenly from the roof of the tunnel and our hero instinctively fires, only to realise he's actually a bloke called Swift who is on our side. But there's no time to apologise. Before Swift even has time to tell us to keep our sh** together, an enemy appears and stabs him in the face.

Pressing on, we catch up with another team-mate, Reznov. "Where is our friend Swift?" he asks.

"Dead," our hero replies.

"Everybody dies, Mason," says Reznov profoundly. "Your turn, my friend. I will follow."

But before we get the chance to see how Mason fairs when leading the way through the tunnel, and whether he learned his lesson regarding the whole Swift incident, it's time to look at the second level on show today. Titled Payback, it's a set piece which involves flying over a Vietnamese valley in a helicopter, dealing death and destruction to the enemy below.

And to think there seemed be a lot of explosions in the other level. It's non-stop here - bases, ships, tanks, tents, telecomms towers, rope bridges, munitions dumps and endless rows of palm trees burst into flame all over the shop. This goes on for several minutes without any kind of retaliatory interruption, suggesting the title of this level has as much to do with rewarding the player with a bit of carefree carnage as it has to do with the plot of the game.

The plot isn't something Treyarch's revealing a great deal about today. Olin does promise us a "deep, complex narrative", but also one that "follows the fine line between complex and confusing". He goes on to admit that "creative liberties" have been taken with regard to the timeline - that helicopter we just saw, for example, didn't actually exist in 1968. "Fun is the most important thing to us; authenticity is second," Olin confirms.

Besides, he says, the truth is often stranger than fiction. "The military advisors we've been talking to did the most crazy, incredible things. People look at some of the sequences in the game and say, 'That's over the top, that's not realistic.'

"But some of the things these guys were telling us were so over the top we said, 'We can't put that in the game. No one would believe it.'"

With that the presentation's over. When I head back out into the booth there's no sign of the military advisor I was chatting to earlier, so I can't ask him about any of the crazy, incredible things he did. He's probably off chopping that wood, splitting those rocks and practicing his steely gaze. Or, you know, blowing sh** up.