Mutual friend Jen is visiting the Sam/Ed collective here at Ed's geek "pad" in the suburbs. We are feeding her hot chocolate and cookies. Jen is more geeky than most girls - not geeky enough to actually write her own operating systems, but certainly geeky enough to appreciate the effort when someone else does. At the moment we are trying to persuade her that the rather inferior chatterbot she has been talking to for the last half-hour is, against all evidence, actually sentient.
"It's just an Amiga 500, after all," she says.
"Any Turing machine can emulate any other Turing machine," explains Ed. "Even if it means going at ten to the eight operations per second instead of ten to the seventeen. If you don't believe us, that's fine. Just don't blame us if you let it loose on the internet and we all end up plugged into a--"
At this point a loud alarm starts blaring somewhere in the house. Ed immediately puts down his drink and runs out of the kitchen. Jen and I follow him through to the lounge, where he has quickly taken a position in front of the television, holding the Xbox's controller. On the screen, a pre-rendered cutscene appears to be playing itself out. A gigantic robot is lifting off on two pillars of flame, ascending into the clouds.
"What's this?" asks Jen.
"It's one of these real-time, all-pervading reality game things," I say. "Do you remember Majestic? That game which kind of took place in the real world - you'd get messages from NPCs on your mobile phone, by email, by fax, all involved in sorting out some mysterious conspiracy. Every month you'd have a different adventure. It felt a little too linear for most players, but it was a pretty spooky and enjoyable experience for all concerned. For me, anyway. This is like one of them, on the Xbox this time. Ed and a whole bunch of other subscribers are involved in this real-time alien invasion of Earth. At any hour of the day or night, one of them might get called up to help defend the planet."
By now Ed's robot has flown all the way out of the Earth's atmosphere and the screen has switched to a first-person shot from inside the cockpit. There are various readings and dials and crosshairs and including weapons of unimaginable destructive power. Ahead of him, radar shows a wave of alien invaders circling in fast towards Earth.
I motion for Jen to sit down. "Ed has to stop all the invaders reaching Earth. It's an age-old concept, but pretty addictive."
A preliminary run over the outskirts of the wave reveals the approximate number of enemies involved and attracts a small amount of fire. Ed shoots a couple of the drones, dives around behind the wave and begins to wreak multi-chaingun havoc. Miniature explosions blossom on the screen.
"Scenery's a little dull," says Jen.
"Space is mostly nothing with a dash of hydrogen."
"There's no sound either."
"'s called realism," says Ed, blowing up two larger drones with well-targeted missiles. Earth looms large behind him - weight of numbers mean that this wave is taking longer than usual to take care of.
"Realism? In a game with aliens and giant robots?"
"What can I say, they were going for total immersion, and believe me, it works..." says Ed, manoeuvring dextrously and dodging incoming fire by mere metres.
"Can I have a go? It looks like fun."
"Uhhh, no," I say. "There are high scores and performance records and such 'n' such. It's quite important that Ed wins this round." Ed nods, but keeps watching the screen. According to his altimeter, he's only a hundred and fifty kilometres above western Europe, and descending fast. Beneath him, the scenery is gradually becoming clearer.
"Are you gonna do it?" asks Jen. There are still four drones left on the screen, each carrying a lethal explosive payload, and targeted on a major European city. Ed is undeterred. He moves to a position directly between all of them, and detonates an electromagnetic pulse. The four drones explode in unison. The robot swoops out of its dive and turns back to base, and Ed puts the controller down and leans back in his seat, relaxing considerably.
"Yup," says Ed, rubbing an eye. "Close one, though." He is sweating quite a lot. His hands are shaking slightly.
"Well, I gotta take off," says Jen, checking her watch. "Thanks for the cookies."
"No problem," says Ed as I see her to the door. We wave through the window as she walks home.
"Nice save there, Sam," says Ed. "Quick thinking."
"Thanks. We're gonna have to tell her one day," say I. "She's not an idiot, and she'll be very upset if she finds out on her own. Are you okay? Need a lie down? That was a close-run thing."
"I'm fine," says Ed, gradually recovering his composure. "But I think they got to within a minute of ground zero that time. That's the closest they've ever got." He looks up at me and sighs. "I could sure make use of that huge base of subscribers you mentioned."
Overhead, there is a dull roar as the robot comes in to land.