You're on an epic journey with Alyx, racing the Combine through the wilderness outside City 17. The Citadel has been destroyed and lies massively across the horizon, with a twister of plasmic energy spiralling into the clouds. Kleiner says it's "the infancy of a superportal". G-Man is back. We learn about his relationship with Alyx. The Combine Advisors move to the fore. Breen's fate is unknown. Double-double-crossing Judith Mossman has a role to play. Dr. Magnusson, one of Gordon's Black Mesa colleagues, is leading an effort in White Forest to launch a satellite. Alyx and Gordon possess the means to access the Combine overworld. Hunters - the raptors of the Strider family - are tracking them. A new muscle car adds to the free-form feel and facilitates fast travel. The Antlion underworld beckons, and Antlion Workers are ready and waiting, corrosive phlegm on standby. Vortigaunts are fighting by your side. Their motivation should become clear.
And somebody's going to die.
Valve hasn't even loaded the game up for me yet, and I've already learned more than I did in the whole of Episode One. When I am wheeled next door, I'm shown six sections taken from the first two-thirds of the game. Wikipedia take note, programmer David Speyrer says they're still fine-tuning the chapters, "but I believe we ended up with six." Does that mean it's going to be another four-hour romp? In a word, no. "We're running at about six-to-eight hours in our playtests here. That's a first-time-through figure," says Speyrer. "It's really varied - you're always being confronted with new environments and situations. It gives it really an epic feel relative to Episode One." That scale won't just be apparent from the run-time, either; Episode Two is immediately impactful. When we grab Gordon by the WSAD he's still in the train carriage that he and Alyx rode away on at the climax of Episode One, only at this point it's lying on its end in a mass of wreckage at the foot of a valley. Clambering down, we find ourselves stuck neck-deep in water with no way out and no weapons. Fortunately Alyx is already outside. Even more fortunately, she's found the gravity gun, which she uses to prise off the door. "I forgot what a kick this thing has," she says, before handing it back. "When I couldn't find you, I kept... I know, I shouldn't have worried." What, no hug?
"The world state of Episode Two has changed considerably," designer Gautam Babbar tells us. "The Citadel's now destroyed." Ah yes, the Citadel. It's the first thing you see when you move over a small hill out of the debris from the train, which is not so much at the bottom of a valley as draped all over it, with sections still hanging from the massive bridge that links the two walls. It reminds me of The Cassandra Crossing. No time to point that out though, because the Combine portal that towers over Ground Zero in the distance is doing something. Bang, it releases a bubble of energy that races towards you and smashes into the valley, collapsing the bridge spectacularly. That's thanks to the new "cinematic physics system", which you may have glimpsed in trailers. Remember the bit in Episode One where you're pinned down in an attic by a Combine flyer, and bits of the floor keep getting knocked out, leaving a lattice of beams that shouted "you're in a game" like nothing else? In Episode Two, they would have just blown the entire place to pieces. "It lets us use a whole new style of special effects techniques for cinematic destruction sequences in real-time," says Speyrer. "You can go into a building and run around it and then the whole building gets blown up."
With the stability of the world in constant flux thanks to those energy bubbles - portal storms - there's every chance we'll be seeing this a lot. But before anything else happens, we're guided through a cave and into a communications outpost. "Dr. Kleiner and my dad are up north at an old missile base," Alyx explains, before climbing up some scaffold into the rafters to try and get things working. She knocks loose an electrical cable, which my trusty gravity gun is well-placed to return to its socket. "Not sure what I did, but it worked," she says. Gordon's typically modest. Kleiner and Eli Vance pop up on the vid-screen, and it's time for some exposition. Like Episode One, Valve wastes no time in explaining what's happening. "The raw discharge of the meltdown has been focused into a coherent beam of portal energy," Kleiner says, discussing the Citadel's present state. "What you're seeing is the infancy of a superportal." Which isn't good, because it puts the Combine on course to reinforce quite dramatically. If they do, says Eli, "it'll be the seven-hour war all over again, except this time we won't last seven minutes." What to do?
We then meet Dr. Magnusson, an old colleague of Gordon's from Black Mesa. He's haughty and assured, and explains that the data packet Alyx retrieved from the Citadel in Episode One is just what he needs. And just what the Combine don't want the resistance to have. In fact, it's "the lynchpin to all of their plans". "Somewhere in that sequence, they would have had to establish a connection with the far-side." Magnusson and co. are busily preparing a satellite, and need that data. "If I'm right about this, and I've no reason to doubt myself," Magnusson pompously intones, "you are carrying the very code Dr. Mossman had hoped to recover." Before anyone can say much more though, the transmission breaks down, and a Combine chopper zooms into view through the windows. It's clear what has to happen: Gordon and Alyx have to head north, to White Forest, and deliver the data packet to the resistance. Game on.
Soon it becomes clear that the Combine know what's going on. In a separate section, we're shown a train of Combine vehicles and units moving over a bridge, as you watch from a shack with Alyx and an unnamed Vortigaunt. There's a Combine Advisor (remember the slug-like creature that produced those psychosomatic energy flashes when you were working through the Citadel in Episode One?) being moved, as well as lots of the choppers, Striders and grunts. "They move north with great purpose," our new Vortigaunt friend grimly acknowledges.
So we have to get a move on. Fortunately we've got a new vehicle to help with that. Episode One was completely devoid of vehicles, despite quite a few in Half-Life 2 itself. "One of the goals for Episode Two is to get players out of City 17 and into the wilderness, and to do some more freeform, less linear gameplay elements, and we thought it would be cool to give players a sweet ride to drive around," Speyrer explains. "In service of that, since we wanted Alyx to be with you throughout, we gave her the ability to ride in the car as a passenger. She can get in and out whenever you do, and she can fight from inside the car." This she does with aplomb as we rocket around the hills and through the trees of the outlying areas of City 17; as a zombie grabs onto the front of the car and we twist and turn, powerless to fight it, Alyx raises a foot and smacks it square in its decaying chops, sending it under the wheels. "We've also enhanced Alyx's combat AI, so you'll see her doing smart things," says Speyrer. "You'll see her hide behind counters and shoot over the top, or take cover next to a window and blindfire when she's pinned down." Still no word on an encore hug though.
But there's no time to lament that because the next section we play quickly changes tack - and our focus - and shifts it to the game's biggest new addition, the Hunter. A relative of the Strider (they're in the same "synth family"), the Hunter's another tripod walker. Artist Ted Backman is said to have drawn inspiration from beetles and crustaceans for the design, while Speyrer, who worked on the AI, says that "behaviourally it's like a predatory dinosaur, sort of like a velociraptor, but with guns". Which hurt. Explosive darts fire from its, I dunno, beak, and they complicate cover-and-fire tactics because they stick in the ground and explode after a few seconds. You have to fight their mobility with your own, and that's no easy thing, because they take what feels like a dozen shotgun rounds to go down, and they work in packs. As I tackle one in a rundown building, the other exits through a hole in the roof, circles round and engages me from behind. I die a couple of times trying to take them down, and then go outside and come up against two more.
This section also throws up a puzzle that involves swapping round electrical wires of differing lengths using the gravity gun, and it brings to mind the relative lack of puzzles in Episode One. Is that going to change? "Episode Two has a little more puzzle density, but they're also much more varied," Gautam Babbar says. Speyrer elaborates, saying we'll see "more set-piece maps, where the whole area is built around this one central theme, maybe a large-scale puzzle". Valve's marketing director Doug Lombardi, keen to set expectations, grins and adds: "I think it's fair to say that there's at least one puzzle in Episode Two that's on the same scale as the crane puzzle in the original Half-Life 2."
Expect combat to puzzle as well. Following a blistering ride in the muscle car, dodging exploding orbs dropped by a chopper, the whirling bird turns on you and a pocket of resistance fighters caught in the midst of huge metal containers with no way out, and - more significantly - no rocket launcher to aid you. What to do? We won't spoil it, but you'll kick yourself when it clicks. And for the record, it doesn't involve the Strider Buster - a Magnusson invention that clamps onto the underside of Striders allowing you to target it for an easier takedown. In fact, we're not even shown the Strider Buster, or Dog's brilliant-looking showdown with one of Half-Life 2's most menacing enemies, although we're assured that the latter "does happen".
We do head underground though, into the Antlion world. "In Half-Life 2 and Episode One Antlions just came out of the ground, and the implication was that there's this whole underground system of tunnels that Antlions lived in. In Episode Two, we take you down into those tunnels and you'll see new species of Antlions and fight them," says Speyrer. "You'll see the ecosystem of the Antlions from the inside." And so we do. Larvae on the tunnel walls crush underfoot and release suit energy to top Gordon up, and terrible screeches puncture the silence. They're from Antlion Workers, a new enemy that takes a couple of shotgun blasts to take down, fires corrosive balls of spit at you and scuttles and leaps with the agility of a regular Antlion. The world itself is an eerie, luminescent blend of blues, greys and light purples, with lots of water, stalagmites and tites jutting out of the ground and ceiling, and a brooding atmosphere that's evocative of the first plunge into the nest of xenomorphs in Aliens. Even though it's utterly different, it feels like a coherent part of the Half-Life world, and reminds us of Xen. Tellingly, Alyx is nowhere to be seen here, although regular Antlions are. But do we get to make them our friends again? "You'll have to play to find out," Speyrer says, giving nothing away.
One thing that strikes us as we tunnel through the Antlion world is the amazing underwater effect - exactly like swimming with your eyes open. "It's our best-looking game ever, which is owed a lot to the fact that we're targeting a higher end this time," Speyrer explains. "PC hardware has moved ahead a lot since we shipped Half-Life 2 and we've tried to stay right on the cutting edge of that hardware. We still scale down - although we're dropping DirectX 7, we scale all the way down for Episode Two." Episode Two borrows elements of DirectX 10 for those whose hardware can take it, although it's not fully DX10-based like Crysis. Not that we're complaining - the overgrown, grassy hills and rundown buildings that pepper the landscape feel at home within the context of the decay witnessed in City 17, and seem to go on for miles. Different, but consistent. Other new effects include phong shading, which gives greater depth and "sheen" to characters, who remain expressive. We can't help giggling when Alyx rolls her eyes at Magnusson's pomp. Meanwhile those Antlion workers even qualify for their own bioluminescent shader effect. Who else but Valve would bother?
We admit, at this point, to being surprised at how much is being shown. Looking back over the last two pages, you might be worried you've seen and heard too much. Lombardi and Speyrer move to reassure us, and that term "mini epic" comes up again. "It's a deliberate choice," says Speyrer of the decision to deal with so many things in Episode Two. "We wanted to really get people into a meaty story, and it's just part of the story we're trying to tell." Lombardi concurs. "I think any trilogy you look at, the second one is always the one that's got all the big reveals that get things charged up a bit." Plus, there's so much left to answer. The big criticism of Half-Life 2 and Episode One was that the cliffhangers swung us over a huge vacuum of information, so it's good to know that we'll get more insight into G-Man, Mossman, the Advisors, the Vortigaunts, and what the rest of the resistance is up to. Bear in mind, also, that we're told at the start of our session that the bits we'll play have been deliberately set up so that we don't get to witness anything that might spoil the experience.
Before we leave, there's time for one more battle, at the White Forest Inn about two-thirds of the way through the game. Steaming past it in the muscle car, Alyx and Gordon are suddenly caught fast in a Combine containment field and funnelled into the Inn itself, as the music ramps up and there's movement all around. What follows is an awesome battle on multiple fronts, as hordes of Combine troops and Hunters descend on the building, blasting holes in it and chasing us up and down the stairs, into the basement, and eventually out into the open. Gordon's on his last sliver of health by the time it finishes, five minutes later, and quite out of breath. It's a fitting climax. Which reminds us - there's speculation, kicked up by friend-of-the-website Tom Francis, of PC Gamer UK fame, that the trilogy will climax in the Arctic. "We're not going to spoil it," Speyrer says. "No matter what Doug said."
But, more important than all that, who the hell dies? The first trailer suggested Alyx was in trouble, but now it's plain that she's at Gordon's side for quite a lot of Episode Two. Are Valve just being mischievous? Perhaps not, says Speyrer. "It's not as much of a misdirection from what you would think when you play," he says. Mystery heightened. At least we got some answers this time though. And with Episode Two's completion potentially just five months away, we hopefully won't have to wait that much longer to get some more. Although, you know, Valve and release dates.
Half-Life 2: Episode Two is currently aiming for October, and will be released on PC, PlayStation 3 and Xbox 360.