Left 4 Dead 2's Dark Carnival unveiled

Valve today revealed the third of five campaigns for Left 4 Dead 2, Dark Carnival, and Eurogamer popped round to the firm's Bellevue office to try it out.

We'll have a comprehensive work-up of what we saw soon, but in the meantime you probably want to check out the first screenshots of Dark Carnival, and hear about things like the new special infected, the Jockey.

The Jockey's a right pain in the neck, appearing out of nowhere and hopping onto one of the survivors' backs. He or she then loses control of movement, allowing the Jockey to steer the pair into dangerous territory, where other infected can pile on the damage.

It's particularly frustrating for the survivors when one of their number is caught straggling, because the Jockey can ride them further and further away from the main group, potentially costing the team even more vital time, health and ammo than, say, a Hunter could by pinning a wayward player.

Dark Carnival itself ("You must be this tall... TO DIE!") begins on a highway, as the survivors inch through and around abandoned cars in the direction of the Ferris wheel and candy stripes on the horizon.

Following a few close shaves and a descent down a slippery hillside (which the AI director saw fit to spice up with a tank - thanks for that), the survivors work through a two-storey motel complex, with roomed-up infected bashing chunks out of every door they pass to try and get at them, and then make their way into the carnival itself, full of infected-packed tents and stalls.

There's a new uncommon common infected to fight - you may remember the hazmat-wearing CEDA infected and riot police with Kevlar from previous reveals - dressed as a clown, who calls other infected over to him. At this stage there's also an Achievement for honking his nose, although these are subject to change.

Valve said that some of the parlor games at the carnival will actually work in the final version, and drew our attention to quirky touches like the peanut man cutouts (he has a nutty nemesis - moustachio) before we hit the climactic point of the two-stage Dark Carnival demo: the merry-go-round crescendo moment.

Waving our katanas, axes and the new electric guitar melee weapons around happily, we set this off, and discovered the goal was to run around it to reach the off switch and stem the growing (and indeed infinite) tide of infected that attack you as you try to do so. Again, the director felt the need to help out by depositing a Witch in our path. Whacking her with the guitar was an error.

There's a lot more to talk about - like the way the Jockey works with other special infected including the other new boys, the Spitter and the Charger, and the simple, immeasurable brilliance of adding proper gibs and limb-loss to the game's existing technical base - but we'll save that for the full preview, coming soon.

There was one other touch to note right at the end though - the classic between-level music you get as you swing the saferoom door closed has been spiced up for Left 4 Dead 2, with a different twist on it for each new campaign.

Check out our previous Left 4 Dead 2 hands-on for more. The game's out for PC and Xbox 360 on 20th November, but launching for Steam on 17th November.