Adam Foster tells me he's "faintly terrified" by the response to his old Half-Life 2 mod Minerva being released on Steam. Tens of thousands have downloaded it in a couple of weeks and he didn't expect that, he insists. But then he also didn't expect the chain of events that unfolded after he first released Minerva back in 2005. Back then he worked for the European Railway Industry doing web development and programming. Today he talks to me from within the hallowed walls of Valve.
Minerva: Metastasis is a collection (and the first chapter) of single-player Half-Life 2 maps renowned for masterfully efficient level design - think of a slaughtered animal in ye olde poor rural community where not a scrap goes to waste - and for an intriguing story about a megalomaniacal narrator called Minerva.
"It's a self-contained storyline about this mysterious island somewhere in the Baltic. You start uncovering mysteries and going deeper and deeper underground and discover quite what the Combine had been building..." Adam Foster explains.
Minerva has nothing to do with the Half-Life 2 storyline but it shares the same universe. "The end result," however, "is something essentially about the size of one of Valve's Episodes." Consider the MIA status of Episode 3, the voracious appetite for anything Half-Life and Foster's current position at Valve, though, and it's not hard to deduce why Minerva's Steam release has caused such a stir.
But the origins of Minerva were not as a way to get a foot in Valve's door, nor as a way for Adam Foster to find fame. Making Minerva was his way of having fun. He gets as much enjoyment building his own Half-Life 2 world as he did playing through Valve's. It was his way of escaping his work in Brussels or his architecture research in the Czech Republic - that other people should want to play Minerva was beside the point. "Minerva was my spare-time project and it was seriously for fun. Instead of long meetings about train bogies and distribution sites and things like that, as my day job, it was yay, I can do something completely different!"
The first Minerva: Metastasis map, Carcinogenesis, was Foster's first ever map for Half-Life 2, though he'd built maps elsewhere before - notably Someplace Else for Half-Life 1. He used an island a bit like Halo's The Silent Cartographer, repurposed the chapter titles to portray Minerva's bidding and added a "funny modem screechy beep noise" to complement it. Carcinogenesis's development ended when Foster hit a technical block - he ran out of space - and took, all told, six months to make. He popped a bow on it and put together a quick and simple website with a couple of screenshots from which to launch it.
He expected a couple of responses. What he didn't expect was Valve's attention and a mention in a news update that caused a stampede. Tens of thousands of Half-Life 2 fans awaiting Episode One - still six months away - downloaded Carcinogenesis. "It used all my monthly bandwidth in a weekend," he says. Adam Foster had become a blip on Valve's radar.
Part two, Downhill Struggle, took another six months and when he released it in April 2006, things got interesting - Valve came knocking. "I was staying with my parents at the time," he recalls, "and one breakfast I said - I hadn't really told anyone I was working on game stuff - 'Um, err, I've been working on this game stuff in my spare time and this company called Valve, they've invited me over for a visit.'
"It got slightly worrying when I was put on business-class ticket."
"It was this weird sensation like being invited over by The Beatles and The Beatles [saying], 'Ooh we quite like your work - continue with it.'"
The great gates of Valve's very real Citadel opened and welcomed outsider Adam Foster deep inside. "I essentially got free-range over lots of Valve stuff," he tells me, "and some stuff, if I were to tell you, I would have to kill you." So Valve had secrets back then that even seven years later we can't know about? "Absolutely," he answers, and I can only think of Half-Life 3.
Valve let Foster play an unfinished Half-Life 2: Episode 1 - he boasts that "there are problems in Episode 1 that do not exist in Episode 1 because of me" - and introduced him to lots of people. With exaggerated modesty he reflects: "It was quite a good visit."
He knew what it all meant of course: Valve had its eye on him. "I was very much on their radar," he says. "It was this weird sensation like being invited over by The Beatles and The Beatles [saying], 'Ooh we quite like your work - continue with it.'" Minerva part three suddenly became much more important. "It was like, yeah, I need to do a good job of this."
That third and final part of Minerva: Metastasis ended up taking three times as long - a year and a half - and comprised two instalments: Depth Charge and Pegasus. Foster was in regular conversation with Valve by this point and he had hands-on help in early 2007 when he flew over for a second visit for what was originally intended as a mod developers' conference, until it was scrapped. With travel already booked he ended up going anyway and, once more, Foster was welcomed by Valve with open arms.
"It was the first time I conducted, essentially, a full-scale Valve play test." He was able to watch professionals explore his work first-hand and see for himself the areas that worked and those that missed the mark. "I learnt a huge amount with that," he says, and it prompted "loads" of improvements. "People have pointed out in Minerva that the first two maps are pretty good, and then, suddenly, it changes. It's like 'oh yeah this is where you had help from Valve'."
The summer months were barren for his European Railway Industry work so he had a rare opportunity to go at Minerva full steam, working dusk 'til dawn. "I got terrifying amounts of work done," he says. The final two Minerva: Metastasis instalments - Depth Charge and Pegasus - were finished and launched a week ahead of Valve's Orange Box and Half-Life 2: Episode 2, and rode the tidal wave of publicity that went with it. "It's like this tiny little boat on this huge wave and I managed to eject at the right point."
"Yes, it's done," was Adam Foster's first reaction. The final parts of Minerva: Metastasis lived up the billing, cementing it as one of Half-Life 2's best ever add-ons, but Valve waited four months until February 2008 before it made its move.
"I got this really short email, kind of, um, would I consider working for Valve - something along those lines, something two sentences long at most. Suddenly my world lurched, like, 'Ooh, maybe.'"
Accepting meant relocating to the US and all the emigration visa-faff that goes with it - and there was only a one-in-two chance of getting the visa he needed at the time. "It felt like there were two potential mes: one version staying in Brussels and the other version going to Seattle." When he got the news that yes, the visa was his, he celebrated with his visiting sister in style: "We shared the most expensive bottle of Stella from a hotel mini-bar imaginable!" What, €10?
He announced the news to his Minerva followers that summer via an ARG (alternate reality game) on his website - a technique he'd go on to use to announce Portal 2 for Valve. The reaction was bitter-sweet; on one hand his fans were happy for him, but on the other they were sad to see plans for Minerva chapter two come to a standstill.
His first day at Valve also happened to be the day Left 4 Dead 1 went to Microsoft certification, and he walked into an office full of crunch. "My first day involved wandering around seeing everyone else like zombies - 'we must finish game; we have finished game' - and it was an interesting experience. At that point I had wondered quite what I had let myself into." But had he arrived a day - even an hour - later, he wouldn't have gotten himself into the game's credits.
"[Valve's] quite strange to work at in that I seriously do not have a boss ... It can be pretty chaotic."
He didn't mention working on Half-Life 2: Episode 3, the game that never materialised - perhaps Valve had made a call around the time he joined, or shortly before, to hold that instalment back and roll it into the mythical Half-Life 3. Who knows? Whatever happened, after a couple of months Adam Foster was nudged towards Portal 2, a project he'd help create the world for.
"The weird thing at Valve," he says, "is that you really do get to choose which projects you work on. It was less of a 'you must work on this'; it was a, 'You might like working on this. We've just started - lots of new stuff to work on.'" There are no wordy portfolios documenting what people are up to, there are just people working on projects and you gravitate towards the one you find interesting.
"It's quite strange to work at in that I seriously do not have a boss. There are people I will definitely listen to but it's more because they have good things to say. There's no one saying 'he must work on this'. If there's a project with bit of work that they really need to get done it's kind of, 'Hey, we need this doing, does anyone want to help out? It's kind of pretty important.' It's more like that. People have to explain why their stuff is worth working on rather than 'you must work on this otherwise you are out'.
"It can be pretty chaotic," he admits. "In a way there's no one Valve: it's lots of overlapping mini-Valves shifting to-and-fro." He reckons Valve is a transplant of the modding community it hires from. "Valve is essentially doing indie stuff on a much larger scale," he says. "I think I'll stick there for a bit."
Before the Steam release, Minerva: Metastasis was downloaded between 300,000 and 400,000 (pre-Steam) times, apparently. That's the first chapter. Adam Foster's talked a bit about his plans for chapter two, Out of Time, which he wanted to set in a snow-covered coastal town - maybe even in Half-Life 2's City 44. The story was going to culminate in a trip to a parallel universe with Minerva to prevent a universe-ending catastrophe. It's all up there in Adam Foster's head, he says, and he's done some art and story tests for it. "But..." he pauses, considering. "[Minerva's] been put to sleep for now. I think she's done. She had a good outing though."
What Adam Foster is working on at Valve he can't tell me. But consider the secrecy, consider his roots as a celebrated Half-Life 1 and Half-Life 2 world and story builder, and consider the reason he was hired in the first place. It all points to Half-Life 3. If such a project does exist, I ask him, would he be working on it? The interview ends with an "ooh, probably".