'Well, I never,' said Mr Bigelow, and moved huffily away with the mincing step he had learned from the Imitation of Life show.

Billy perceived his friend's pain. It embarrassed him. He was thirty-four, a year and a bit older than Marvin, nearly a man. He had a good job as foreman of Assembly Line 23 in Peterson's Box Factory. He clung to adolescent ways, of course, but he knew that his age presented him with certain obligations. Thus, he cross-circuited his fear of embarrassment, and spoke to his oldest friend in clear.

'Marvin – what's the matter?'

Marvin shrugged his shoulder, quirked his mouth, and drummed aimlessly with his fingers. He said, 'Oiga, hombre, ein Kleinnachtmusik es demasiado, nicht wahr? The Todt you ruve to touch …'

'Straighten it,' Billy said, with a quiet dignity beyond his years.

'I'm sorry,' Marvin said, in clear. 'It's just – oh, Billy, I really do want to travel so badly!'

Billy nodded. He was aware of his friend's obsession. 'Sure,' he said. 'Me too.'

'But not as bad. Billy – I got the burns.'

His skoboldash sundae arrived. Marvin ignored it, and poured out his heart to his lifelong friend, 'Mira, Billy, it's really got me wound tighter than a plastic retriever coil. I think of Mars and Venus, and really faraway places like Aldeberan and Antares and – I mean, gosh, I just can't stop thinking about it all. Like the Talking Ocean of Procyon IV, and the tripartritate hominoids of Allua II, and it's like I'll simply die if I don't really and actually see those places.'

'Sure,' his friend said. 'I'd like to see them, too.'

'No, you don't understand,' Marvin said. 'It's not just to see – it's – it's like – it's worse than – I mean, I can't just live here in Stanhope the rest of my life even though it's fun and I got a nice job and I'm dating some really guapa girls but heck, I can't just marry some girl and raise kids and – and – there's gotta be something more!'

Then Marvin lapsed into adolescent incoherence. But something of his feelings had come through the wild torrent of his words, and his friend nodded sagely.

'Marvin,' he said softly, 'I read you five by five, honest to Sam I do. But gee, even interplanetary travel costs fortunes. And interstellar stuff is just plain impossible.'

'It's all possible,' Marvin said, 'if you use Mindswap.'

'Marvin! You can't mean that!' His friend was too shocked to avoid the exclamation.

'I can!' Marvin said. 'And by the Christo malherido, I'm going to!'

That shocked them both. Marvin hardly ever used bad language, and his friend could see the considerable stress he was under to use such an expression, even though coded. And Marvin, having said what he had said, recognized the implacable nature of his resolve. And having expressed it, he found it less frightening to contemplate the next step, that of doing something about it.

'But you can't,' Billy said. 'Mindswap is – well, it's dirty!'

' "Dirty he who dirty thinks, Cabrón." '

'No, seriously. You don't want some sand-grubbing old Martian inside your head? Moving your legs and arms, looking out of your eyes, touching you, and maybe even-'

Marvin cut him off before he said something really bad. 'Mira,' he said, 'recuerda que I'll be in his body, on Mars, so he'll be having the same embarrassments.'

'Martians haven't got no sense of embarrassment,' Billy said.

'That's just not true,' Marvin said. Although younger, he was in many ways more mature than his friend. He had been an apt student in Comparative Interstellar Ethics. And his intense desire to travel rendered him less provincial in his attitudes, more prepared to see the other creature's point of view, than his friend. From the age of twelve, when he had learned how to read, Marvin had studied the manners and modes of many different races in the galaxy. Always he had endeavoured to view those creatures through their own eyes, and to understand their motivations in terms of their own unique psychologies. Furthermore, he had scored in the 95th percentile in Projective Empathy, thus establishing his raw potentiality for successful extraterrestrial relationships. In a word, he was as prepared for travel as it is possible for a young man to become who has lived all his life in a small town in the hinterlands of Earth.

That afternoon, alone in his attic room, Marvin opened his encyclopedia. It had been his companion and friend ever since his parents bought it for him when he was nine. Now he set the comprehension level at 'simple', the scan rate at 'rapid', punched his questions, and settled back as the little red and green lights flashed on.

'Hi, fellows,' the tapecorder said in its fruitily enthusiastic voice. 'Today – let's talk about Mindswap!'

There followed a historical section, which Marvin ignored. His attention returned when he heard the tapecorder saying:

'So let's just consider Mind as a kinda electroform or maybe even a subelectroform entity. You pro'lly remember from our previous talk that Mind is thought to have begun as a projection of our bodily processes, and to have evolved into a quasi-independent entity. You know what that means, fellas. It means it's like you got a little Man in your head – but not quite. Isn't that quazi?'

The tapecorder laughed modestly at its little joke, then went on:

'So what have we got out of this mishmash? Well, kids, we got ourselves a sort of symbiotic situation, mind and bodywise, even though Mr Mind is inclined to a sort of parasitism. But still, each can exist – theoretically – without the other. Or anyhow, that's what the Big Thinkers say.'

Marvin skimmed.

'Now as for projecting the mind – well, guys, just think of throwing a ball …

'Mental into physical, and vice versa. Ultimately, they are forms of each other, just like matter and energy. Of course, we have yet to discover …

'But of course, we have only a pragmatic knowledge of it. We might consider, just for a very brief moment, Van Voorhes' concept of Agglutinative Reform, and the Lagos University Theory of Relative Absolutes. Of course, these theories raise more questions than they answer …

'… and the whole works is made possible only by the somewhat surprising lack of an immuniform reaction.

'The actual practice of Mindswap utilizes mechanical-hypnotic techniques such as induced relaxation, pinpoint fixation, and the use of a mind-positive substance, such as Williamite, as a narrow-beam focuser and intensifier. Feedback programming …

'Once learned, of course, you can Swap without mechanical aids, usually employing sight as focus …'

Marvin turned off the encyclopedia and thought about space, and the many planets, and the exotic inhabitants of those planets. He thought about Mindswap. He thought: tomorrow I could be on Mars. Tomorrow I could be a Martian …

He jumped to his feet 'By jingo!' he cried, striking palm of his left hand with his right fist, 'I'll do it!'

The strange alchemy of decision had transformed him. Without hesitation he packed a light suitcase, left a note for his parents, and caught the jet to New York.