'We are close. But more like... I know. Once mom and I got stuck in the subway in New York. The power went out, there were no announcements or anything, and we were there for about two hours with a couple dozen people who didn't know each other. We all ended up talking like old friends, though we even sang "happy birthday" to an old lady who just turned seventy-eight. We were all best friends because we were going through a bad thing together.'

'They call that "crisis syndrome".'

'Yeah. That's it. The Doctor and I are always going through one crisis after another.'

Bob rounded the corner and glanced at us. Peri looked awkward all of a sudden, but he didn't seem to register anything. We followed him inside.

The Doctor was saying, 'We have a dialtone. Bless you, Bob,' and feeding a phone number to the modem. 'The sun reflecting upon the mud of strands and sh.o.r.es is unpolluted in his beam,' he declaimed. 'Now it's time to test that theory and wallow a little in the MUD with Swan.'

'Doctor,' said Peri, 'what are you talking about?'

I knew that one. 'Multiple User Dungeon,' I told her 'It's a s.p.a.ce inside a computer, like a map in a game of D&D. You can walk from room to room, look at what's there, and meet other people and talk to them. The mud program runs everything, like a Dungeon Master.'

'Neutral ground,' said the Doctor. We watched over his shoulder as the Apple II's modem shook hands with another modem somewhere else in the States.

The first step was to create a 'character' that would represent him in the miniature imaginary world. The Doctor didn't bother with details like appearance or even gender, just a code name, Merryman. The MUD was set up so that guests could appear as anonymous wraiths in the public areas of the game. Normally partic.i.p.ants would go to great lengths to create their appearance. For Swan and the Doctor's meeting, play-acting wasn't necessary.

The Doctor's featureless character appeared out of nowhere in the imaginary world:

Welcome to the Dungeon of Doom. You are standing in a forest clearing facing north.

In front of you is a cliff wall. In the wall is a large opening, the doorway to the Caves of Catastrophe.

'Well, you obviously don't want to go in there,' said Peri.

We all looked at her. 'It was just a joke.'

'I doubt there's anywhere else to go, said the Doctor. He typed:

go north

A few moments later, the computer answered: You are standing in the entrance cave.

Pa.s.sages lead off to the east and west. You can see daylight through a doorway in the south.

'Well, this could take all day, said Peri.

'Ah, but I know a way to speed things up.' The Doctor typed:

Ziz-zy, zuz-zy, zik!

The computer responded:

The genie appears in a puff of smoke.

'Welcome, guest' he says. 'Where would you like me to take you?'

The Doctor typed:

genie living_room

And the program responded:

You enter a pleasant living room. There are comfortable chairs scattered about, rugs and lamps, and a roaring fireplace.

Fionnuala is here.

The genie departs in a puff of smoke.

'Fionnuala,' said the Doctor. 'A woman changed into a swan in Irish legend. She's just where I asked her to be.'

From time to time, the net, even just the phone gives me a case of the profound heebie-jeebies. It's a feeling of being watched. Have you ever had a prank phone call, and been really creeped out by the fact that someone could just call you up like that, enter your home in a sense, and you had no idea of where they were or who they were? Worse still, have you ever had a call where someone said 'I can see you through the window, I'm outside your house?' I haven't, but Sally did once. We agreed it was probably bulls.h.i.t, but she insisted on sleeping at my place for a week.

I had that feeling as the Doctor joined Sarah Swan for their little chat in the living room of the imaginary house. There was something unnerving about Swan waiting for him there, another pseudonymous, abstract creature. It could, in theory, have been anyone. We could have been anyone. It was only our agreement, our mutual acceptance that this was a place and we were going to meet there and talk, that gave any of it any substance, any meaning at all.

Imagine them sitting in that sketch of a room the black, silent, empty s.p.a.ce inside the network. Imagine the edges of walls and objects drawn in lines the same livid green as the writing on a monitor. Their chairs are luminous stick-figures.

They are only outlines of words, a conversation punctuated by electrical lacunae, their shapes traced by the flicker of the cursor as it darts across the screen.

'What is it you want, Sarah Swan?' asks the Doctor.

Between each line of their dialogue there is a pause, as if they are gathering their thoughts. It's actually the slow motion of the machines and the miles of wire that connect them.

Swan says, 'I want to own something that no-one else in the world has.'

'What are you willing to pay for that privilege?'

Swan responds,'Ha ha ha. I ALREADY HAVE IT. It's too late to demand payment.'

'That's not my meaning,' retorts the Doctor.

The Doctor says,'What will be the cost to yourself? Since no-one else in the world possesses what you possess, no-one can give you advice about it. No warnings, no rescue.

A very long pause. Then,'You warn me.'

'I can only warn you to give it up. You know you don't know what you're dealing with.'

'Every human advance is dogged by nay-sayers and doom-sayers.'

'This is not a HUMAN ADVANCE!' thunders the Doctor.

'This is an intrusion from well outside the human sphere.'

'Ha ha ha ha ha.'

'If that's too extraordinary to squeeze into your mind, then consider this: you did not invent this thing. You have no way to understand its workings. Rather than an advance, this is a leap into a realm riddled with unknowns.'

'The problem is not me,' argues Swan. 'It's you. You have the knowledge and you won't give it to me. It's your fault if something goes wrong.'

'Then let's meet in real life.' (In real life, the Doctor was ranting about Swan's cheap manipulation of ethics.) 'I can help you understand the component, a.s.sess the danger.'

'Ha ha ha ha ha.'

Swan stands up from her imaginary chair and walks out of the room. The Doctor doesn't hesitate, but follows her through the exit:

The door opens into a large unlit cavern. You can hear the sound of running water. An unlit torch is here. Fionnuala is here.

The Doctor has nothing to light the torch with. He stands in mathematical darkness, aware of Swan's presence but unable to see her. It doesn't stop him from trying to get the message across.

'Your petty greed will not only endanger yourself and those you come into contact with think of the consequences if those with ambitions beyond your own take your toy away from you. Just for once, think of something larger than yourself.'

Swan doesn't reply. He talks about danger, but doesn't give her a shred of evidence. She's simply waiting for him to agree, confident he'll have to give in.

Luis enters the cave.

'SWAN!' shouts the newcomer. 'I KNOW THAT'S YOU.