He pulled his newly acquired credit card from his pocket, slid it into a crack where the window met its surrounding frame, and did something a rocket would not have been able to do. He wiggled it around a bit. He felt a catch slip. He slid the window open and almost fell backwards off the ledge laughing, giving thanks as he did so for the Great Ventilation and Telephone Riots of SrDt 3454 The Great Ventilation and Telephone Riots of SrDt 3454 had started off as just a lot of hot air. Hot air was, of course, the problem that ventilation was supposed to solve and generally it had solved the problem reasonably well up to the point when someone invented air-conditioning, which solved the problem far more throbbingly.

And that was all well and good provided you could stand the noise and the dribbling until someone else came up with something even sexier and smarter than air-conditioning which was called in-building climate control.

Now this was quite something.

The major differences from just ordinary air-conditioning were that it was thrillingly more expensive, involved a huge amount of sophisticated measuring and regulating equipment which was far better at knowing, moment by moment, what kind of air people wanted to breathe than mere people did.

It also meant that, to be sure that mere people didn't muck up the sophisticated calculations which the system was making on their behalf, all the windows in the buildings were built sealed shut. This is true.

While the systems were being installed, a number of people who were going to work in the buildings found themselves having conversations with Breathe-o-Smart systems fitters which went something like this:

'But what if we want to have the windows open?'

'You won't want to have the windows open with new Breathe– o-Smart.

'Yes but supposing we just wanted to have them open for a little bit?'

'You won't want to have them open even for a little bit. The new Breathe-o-Smart system will see to that.'

'Hmmm.'

'Enjoy Breathe-o-Smart!'

'OK, so what if the Breathe-o-Smart breaks down or goes wrong or something?'

'Ah! One of the smartest features of the Breathe-o-Smart is that it cannot possibly go wrong. So. No worries on that score. Enjoy your breathing now, and have a nice day.'

(It was, of course, as a result of the Great Ventilation and Telephone Riots of SrDt 3454, that all mechanical or electri– cal or quantum-mechanical or hydraulic or even wind, steam or piston-driven devices, are now required to have a certain legend emblazoned on them somewhere. It doesn't matter how small the object is, the designers of the object have got to find a way of squeezing the legend in somewhere, because it is their attention which is being drawn to it rather than necessarily that of the user's.

The legend is this:

'The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.') Major heat waves started to coincide, with almost magical precision, with major failures of the Breathe-o-Smart systems. To begin with this merely caused simmering resentment and only a few deaths from asphyxiation.

The real horror erupted on the day that three events happened simultaneously. The first event was that Breathe-o-Smart Inc. issued a statement to the effect that best results were achieved by using their systems in temperate climates.

The second event was the breakdown of a Breathe-o-Smart system on a particularly hot and humid day with the resulting evacuation of many hundreds of office staff into the street where they met the third event, which was a rampaging mob of long– distance telephone operators who had got so twisted with having to say, all day and every day, 'Thank you for using BS&S' to every single idiot who picked up a phone that they had finally taken to the streets with trash cans, megaphones and rifles.

In the ensuing days of carnage every single window in the city, rocket-proof or not, was smashed, usually to accompanying cries of 'Get off the line, asshole! I don't care what number you want, what extension you're calling from. Go and stick a firework up your bottom! Yeeehaah! Hoo Hoo Hoo! Velooooom! Squawk!' and a variety of other animal noises that they didn't get a chance to practise in the normal line of their work.

As a result of this, all telephone operators were granted a constitutional right to say 'Use BS&S and die!' at least once an hour when answering the phone and all office buildings were required to have windows that opened, even if only a little bit.

Another, unexpected result was a dramatic lowering of the suicide rate. All sorts of stressed and rising executives who had been forced, during the dark days of the Breathe-o-Smart tyr– anny, to jump in front of trains or stab themselves, could now just clamber out on to their own window ledges and leap off at their leisure. What frequently happened, though, was that in the moment or two they had to look around and gather their thoughts they would suddenly discover that all they had really needed was a breath of air and a fresh perspective on things, and maybe also a farm on which they could keep a few sheep.

Another completely unlooked for result was that Ford Prefect, stranded thirteen stories up a heavily armoured building armed with nothing but a towel and a credit card was nevertheless able to clamber through a supposedly rocket-proof window to safety.

He closed the window neatly after him, having first allowed Colin to follow him through, and then started to look around for this bird thing.

The thing he realised about the windows was this: because they had been converted into openable windows after they had first been designed to be impregnable, they were, in fact, much less secure than if they had been designed as openable windows in the first place.

Hey ho, it's a funny old life, he was just thinking to himself, when he suddenly realised that the room he had gone to all this trouble to break into was not a very interesting one.

He stopped in surprise.

Where was the strange flapping shape? Where was anything that was worth all this palaver– the extraordinary veil of secrecy that seemed to lie over this room and the equally extraordinary sequence of events that had seemed to conspire to get him into it?

The room, like every other room in this building now, was done out in some appallingly tasteful grey. There were a few charts and drawings on the wall. Most of them were meaningless to Ford, but then he came across something that was obviously a mock-up for a poster of some kind.

There was a kind of bird-like logo on it, and a slogan which said 'The Hitch Hiker's Guide to the Galaxy Mk II: the single most astounding thing of any kind ever. Coming soon to a dimension near you.' No more information than that.

Ford looked around again. Then his attention was gradually drawn to Colin, the absurdly over-happy security robot, who was cowering in a corner of the room gibbering with what seemed strangely like fear.

Odd, thought Ford. He looked around to see what it was that Colin might have been reacting to. Then he saw something that he hadn't noticed before, Iying quietly on top of a work bench.

It was circular and black and about the size of a small side plate. Its top and its bottom were smoothly convex so that it resembled a small lightweight throwing discus.

Its surfaces seemed to be completely smooth, unbroken and featureless.

It was doing nothing.

Then Ford noticed that there was something written on it. Strange. There hadn't been anything written on it a moment ago and now suddenly there was. There just didn't seem to have been any observable transition between the two states.

All it said, in small, alarming letters was a single word: