This was because Reason was in fact out to lunch.
A hole had just appeared in the Galaxy. It was exactly a nothingth of a second long, a nothingth of an inch wide, and quite a lot of million light years from end to end.
As it closed up lots of paper hats and party balloons fell out of it and drifted off through the universe. A team of seven three-foot-high market analysts fell out of it and died, partly of asphyxication, partly of surprise.
Two hundred and thirty-nine thousand lightly fried eggs fell out of it too, materializing in a large woobly heap on the famine-struck land of Poghril in the Pansel system.
The whole Poghril tribe had died out from famine except for one last man who died of cholesterol poisoning some weeks later.
The nothingth of a second for which the hole existed reverberated backwards and forwards through time in a most improbable fashion. Somewhere in the deeply remote past it seriously traumatized a small random group of atoms drifting through the empty sterility of space and made them cling together in the most extraordinarily unlikely patterns. These patterns quickly learnt to copy themselves (this was part of what was so extraordinary of the patterns) and went on to cause massive trouble on every planet they drifted on to. That was how life began in the Universe.
Five wild Event Maelstroms swirled in vicious storms of unreason and spewed up a pavement.
On the pavement lay Ford Prefect and Arthur Dent gulping like half-spent fish.
``There you are,'' gasped Ford, scrabbling for a fingerhold on the pavement as it raced through the Third Reach of the Unknown, ``I told you I'd think of something.''
``Oh sure,'' said Arthur, ``sure.''
``Bright idea of mine,'' said Ford, ``to find a passing spaceship and get rescued by it.''
The real universe arched sickeningly away beneath them. Various pretend ones flitted silently by, like mountain goats. Primal light exploded, splattering space-time as with gobbets of junket. Time blossomed, matter shrank away. The highest prime number coalesced quietly in a corner and hid itself away for ever.
``Oh come off it,'' said Arthur, ``the chances against it were astronomical.''
``Don't knock it, it worked,'' said Ford.
``What sort of ship are we in?'' asked Arthur as the pit of eternity yawned beneath them.
``I don't know,'' said Ford, ``I haven't opened my eyes yet.''
``No, nor have I,'' said Arthur.
The Universe jumped, froze, quivered and splayed out in several unexpected directions.
Arthur and Ford opened their eyes and looked about in considerable surprise.
``Good god,'' said Arthur, ``it looks just like the sea front at Southend.''
``Hell, I'm relieved to hear you say that,'' said Ford.
``Because I thought I must be going mad.''
``Perhaps you are. Perhaps you only thought I said it.''
Ford thought about this.
``Well, did you say it or didn't you?'' he asked.
``I think so,'' said Arthur.
``Well, perhaps we're both going mad.''
``Yes,'' said Arthur, ``we'd be mad, all things considered, to think this was Southend.''
``Well, do you think this is Southend?''
``So do I.''
``Therefore we must be mad.''
``Nice day for it.''
``Yes,'' said a passing maniac.
``Who was that?'' asked Arthur
``Who --- the man with the five heads and the elderberry bush full of kippers?''
``I don't know. Just someone.''
They both sat on the pavement and watched with a certain unease as huge children bounced heavily along the sand and wild horses thundered through the sky taking fresh supplies of reinforced railings to the Uncertain Areas.
``You know,'' said Arthur with a slight cough, ``if this is Southend, there's something very odd about it ...''
``You mean the way the sea stays steady and the buildings keep washing up and down?'' said Ford. ``Yes I thought that was odd too. In fact,'' he continued as with a huge bang Southend split itself into six equal segments which danced and span giddily round each other in lewd and licentious formation, ``there is something altogether very strange going on.''
Wild yowling noises of pipes and strings seared through the wind, hot doughnuts popped out of the road for ten pence each, horrid fish stormed out of the sky and Arthur and Ford decided to make a run for it.
They plunged through heavy walls of sound, mountains of archaic thought, valleys of mood music, bad shoe sessions and footling bats and suddenly heard a girl's voice.
It sounded quite a sensible voice, but it just said, ``Two to the power of one hundred thousand to one against and falling,'' and that was all.
Ford skidded down a beam of light and span round trying to find a source for the voice but could see nothing he could seriously believe in.
``What was that voice?'' shouted Arthur.
``I don't know,'' yelled Ford, ``I don't know. It sounded like a measurement of probability.''
``Probability? What do you mean?''
``Probability. You know, like two to one, three to one, five to four against. It said two to the power of one hundred thousand to one against. That's pretty improbable you know.''
A million-gallon vat of custard upended itself over them without warning.
``But what does it mean?'' cried Arthur.
``What, the custard?''
``No, the measurement of probability!''
``I don't know. I don't know at all. I think we're on some kind of spaceship.''
``I can only assume,'' said Arthur, ``that this is not the first-class compartment.''
Bulges appeared in the fabric of space-time. Great ugly bulges.
``Haaaauuurrgghhh ...'' said Arthur as he felt his body softening and bending in unusual directions. ``Southend seems to be melting away ... the stars are swirling ... a dustbowl ... my legs are drifting off into the sunset ... my left arm's come off too.'' A frightening thought struck him: ``Hell,'' he said, ``how am I going to operate my digital watch now?'' He wound his eyes desperately around in Ford's direction.
``Ford,'' he said, ``you're turning into a penguin. Stop it.''
Again came the voice.
``Two to the power of seventy-five thousand to one against and falling.''
Ford waddled around his pond in a furious circle.
``Hey, who are you,'' he quacked. ``Where are you? What's going on and is there any way of stopping it?''
``Please relax,'' said the voice pleasantly, like a stewardess in an airliner with only one wing and two engines one of which is on fire, ``you are perfectly safe.''
``But that's not the point!'' raged Ford. ``The point is that I am now a perfectly save penguin, and my colleague here is rapidly running out of limbs!''
``It's alright, I've got them back now,'' said Arthur.
``Two to the power of fifty thousand to one against and falling,'' said the voice.
``Admittedly,'' said Arthur, ``they're longer than I usually like them, but ...''
``Isn't there anything,'' squawked Ford in avian fury, ``you feel you ought to be telling us?''
The voice cleared its throat. A giant petit four lolloped off into the distance.
``Welcome,'' the voice said, ``to the Starship Heart of Gold.''
The voice continued.
``Please do not be alarmed,'' it said, ``by anything you see or hear around you. You are bound to feel some initial ill effects as you have been rescued from certain death at an improbability level of two to the power of two hundred and seventy-six thousand to one against --- possibly much higher. We are now cruising at a level of two to the power of twenty-five thousand to one against and falling, and we will be restoring normality just as soon as we are sure what is normal anyway. Thank you. Two to the power of twenty thousand to one against and falling.''
The voice cut out.
Ford and Arthur were in a small luminous pink cubicle.
Ford was wildly excited.
``Arthur!'' he said, ``this is fantastic! We've been picked up by a ship powered by the Infinite Improbability Drive! This is incredible! I heard rumors about it before! They were all officially denied, but they must have done it! They've built the Improbability Drive! Arthur, this is ... Arthur? What's happening?''
Arthur had jammed himself against the door to the cubicle, trying to hold it closed, but it was ill fitting. Tiny furry little hands were squeezing themselves through the cracks, their fingers were inkstained; tiny voices chattered insanely.
Arthur looked up.
``Ford!'' he said, ``there's an infinite number of monkeys outside who want to talk to us about this script for Hamlet they've worked out.''