“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.”

The Infinite Improbability Drive is a wonderful new method of crossing vast interstellar distances in a mere nothingth of a second, without all that tedious mucking about in hyperspace.

It was discovered by a lucky chance, and then developed into a governable form of propulsion by the Galactic Government’s research team on Damogran.

This, briefly, is the story of its discovery.

The principle of generating small amounts of finite improbability by simply hooking the logic circuits of a Bambleweeny 57 Sub-Meson Brain to an atomic vector plotter suspended in a strong Brownian Motion producer (say a nice hot cup of tea) were of course well understood—and such generators were often used to break the ice at parties by making all the molecules in the hostess’s undergarments leap simultaneously one foot to the left, in accordance with the Theory of Indeterminacy.

Many respectable physicists said that they weren’t going to stand for this—partly because it was a debasement of science, but mostly because they didn’t get invited to those sort of parties.

Another thing they couldn’t stand was the perpetual failure they encountered in trying to construct a machine which could generate the infinite improbability field needed to flip a spaceship across the mind-paralysing distances between the furthest stars, and in the end they grumpily announced that such a machine was virtually impossible.

Then, one day, a student who had been left to sweep up the lab after a particularly unsuccessful party found himself reasoning this way:

If, he thought to himself, such a machine is a virtual impossibility, then it must logically be a finite improbability. So all I have to do in order to make one is to work out exactly how improbable it is, feed that figure into the finite improbability generator, give it a fresh cup of really hot tea… and turn it on!

He did this, and was rather startled to discover that he had managed to create the long sought after golden Infinite Improbability generator out of thin air.

It startled him even more when just after he was awarded the Galactic Institute’s Prize for Extreme Cleverness he got lynched by a rampaging mob of respectable physicists who had finally realized that the one thing they really couldn’t stand was a smartass.

The Improbability-proof control cabin of the Heart of Gold looked like a perfectly conventional spaceship except that it was perfectly clean because it was so new. Some of the control seats hadn’t had the plastic wrapping taken off yet. The cabin was mostly white, oblong, and about the size of a smallish restaurant. In fact it wasn’t perfectly oblong: the two long walls were raked round in a slight parallel curve, and all the angles and corners were contoured in excitingly chunky shapes. The truth of the matter is that it would have been a great deal simpler and more practical to build the cabin as an ordinary three-dimensional oblong room, but then the designers would have got miserable. As it was the cabin looked excitingly purposeful, with large video screens ranged over the control and guidance system panels on the concave wall, and long banks of computers set into the convex wall. In one corner a robot sat humped, its gleaming brushed steel head hanging loosely between its gleaming brushed steel knees. It too was fairly new, but though it was beautifully constructed and polished it somehow looked as if the various parts of its more or less humanoid body didn’t quite fit properly. In fact they fitted perfectly well, but something in its bearing suggested that they might have fitted better.

Zaphod Beeblebrox paced nervously up and down the cabin, brushing his hands over pieces of gleaming equipment and giggling with excitement.

Trillian sat hunched over a clump of instruments reading off figures. Her voice was carried round the Tannoy system of the whole ship.

“Five to one against and falling…” she said, “four to one against and falling… three to one… two… one… probability factor of one to one… we have normality, I repeat we have normality.” She turned her microphone off—then turned it back on, with a slight smile and continued: “Anything you still can’t cope with is therefore your own problem. Please relax. You will be sent for soon.”

Zaphod burst out in annoyance: “Who are they Trillian?”

Trillian span her seat round to face him and shrugged.

“Just a couple of guys we seem to have picked up in open space,” she said. “Section ZZ9 Plural Z Alpha.”

“Yeah, well that’s a very sweet thought Trillian,” complained Zaphod, “but do you really think it’s wise under the circumstances? I mean, here we are on the run and everything, we must have the police of half the Galaxy after us by now, and we stop to pick up hitchhikers. OK, so ten out of ten for style, but minus several million for good thinking, yeah?”

He tapped irritably at a control panel. Trillian quietly moved his hand before he tapped anything important. Whatever Zaphod’s qualities of mind might include—dash, bravado, conceit—he was mechanically inept and could easily blow the ship up with an extravagant gesture. Trillian had come to suspect that the main reason why he had had such a wild and successful life that he never really understood the significance of anything he did.

“Zaphod,” she said patiently, “they were floating unprotected in open space… you wouldn’t want them to have died would you?”

“Well, you know… no. Not as such, but…”

“Not as such? Not die as such? But?” Trillian cocked her head on one side.

“Well, maybe someone else might have picked them up later.”

“A second later and they would have been dead.”

“Yeah, so if you’d taken the trouble to think about the problem a bit longer it would have gone away.”

“You’d been happy to let them die?”