Or something?'

Talliaferro said, 'Come on! First big interplanetary astronomical convention in history is no place for glooming. And among friends, too!'

Kaunas said suddenly, 'It's Earth. It doesn't feel right. I can't get used to it.' He shook his head but his look of depression remained.

Talliaferro said, 'I know. I'm so heavy. It takes all the energy out of me. At that, you're better off than I am, Kaunas. Mercurian gravity is 0-4 normal. On the Moon, it's only 0 - I6.' He interrupted Ryger's beginning of a sound by saying, 'And on Ceres they use pseudo-grav fields adjusted to 0-8. You have no problems at all, Ryger.'

The Cerian astronomer looked annoyed. 'It's the open air. Going outside without a suit gets me.'

'Right,' agreed Kaunas. 'And letting the Sun beat down on you. Just letting it.'

Talliaferro found himself insensibly drifting back in time. They had not changed much. Nor, he thought, had he himself. They were all ten years older, of course. Ryger had put on some weight and Kaunas' thin face had grown a bit leathery, but he would have recognized either if he had met him without warning.

He said, 'I don't think it's Earth getting us. Let's face it.'

Kaunas looked up sharply. He was a little fellow with quick, nervous movements of his hands and habitually wore clothes that looked a shade too large for him.

He said, 'Villiers! I know. I think about him sometimes.' Then, with an air of desperation, 'I got a letter from him.'

Ryger sat upright, his olive complexion darkening further, and said with energy, 'You did? When?'

'A month ago.'

Ryger turned to Talliaferro. 'How about you?' Talliaferro blinked placidly and nodded.

Ryger said, 'He's gone crazy. He claims he's discovered a practical method of mass transference through space. -He told you two also? -That's it, then. He was always a little bent. Now he's broken.'

He rubbed his nose fiercely, and Talliaferro thought of the day Villiers had broken it.

For ten years Villiers had haunted them like the vague shadow of a guilt that wasn't really theirs. They had gone through their graduate work together, four picked and dedicated men being trained for a profession that had reached new heights in this age of interplanetary travel.

The observatories were opening on the other worlds, surrounded by vacuum, unblurred by air.

There was the Lunar Observatory, from which Earth and the inner planets could be studied; a silent world in whose sky the home planet hung suspended.

Mercury Observatory, closest to the Sun, perched at Mercury's north pole, where the terminator moved scarcely at all, and the Sun was fixed on the horizon and could be studied in the minutest detail.

Ceres Observatory, newest, most modern, with its range extending from Jupiter to the outermost galaxies.

There were disadvantages, of course. With interplanetary travel still difficult, leaves would be few, anything like normal life virtually impossible, but this was a lucky.generation. Coming scientists would find the fields of knowledge well reaped and, until the invention of an interstellar drive, no new horizon as capacious as this one would be opened.

These lucky four, Talliaferro, Ryger, Kaunas, and Villiers, were to be in the position of a Galileo, who, by virtue of owning the first real telescope, could not point it anywhere in the sky without making a major discovery.

But then Romano Villiers had fallen sick and it was rheumatic fever. Whose fault was that? His heart had been left leaking and limping. 

He was the most brilliant of the four, the most hopeful, the most intense-and he could not even finish his schooling and get his doctorate.

Worse than that, he could never leave Earth; the acceleration of a spaceship's takeoff would kill him. Talliaferro was marked for the Moon, Ryger for Ceres, Kaunas for Mercury. Only Villiers stayed behind, a life prisoner of Earth.

They had tried telling their pity and Villiers had rejected it with something approaching hate. He had railed at them and cursed them. When Ryger lost his temper and lifted his fist, Villiers had sprung at him screaming and broken his nose.

Obviously Ryger hadn't forgotten that, as he caressed his nose gingerly with one finger.

Kaunas' forehead was an uncertain washboard of wrinkles. 'He's at the Convention, you know. He's got a room in the hotel-405.'

'I won't see him,' said Ryger.

'He's coming up here. He said he wanted to see us. I thought he said nine. He'll be here any minute.'

'In that case,' said Ryger, 'if you don't mind, I'm leaving.'

Talliaferro said, 'Oh, wait awhile. What's the harm in seeing him?'

'Because there's no point. He's insane.'

'Even so. Let's not be petty about it. Are you afraid of him?'

'Afraid!' Ryger looked contemptuous.

'Nervous, then. What is there to be so nervous about?'

'I'm not nervous,' said Ryger.

'Sure you are. We all feel guilty about him, and without real reason. Nothing that happened was our fault.' But he was speaking defensively and he knew it.

And when, at that point, the door signal sounded, all three jumped and turned to stare uneasily at the barrier that stood between themselves and Villiers.

The door opened and Romano Villiers walked in. The others rose stiffly to greet him, then remained standing in embarrassment, without one hand being raised.

He stared them down sardonically.

He's changed, thought Talliaferro.

He had. He had shrunk in almost every dimension. A gathering stoop even made him seem shorter. The skin of his scalp glistened through thinning hair, the skin on the back of his hands was ridged crookedly with bluish veins. He looked ill. There seemed nothing to link him to the memory of the past except for his trick of shading his eyes with one hand when he stared intently and, when he spoke, the even, controlled baritone of his voice.

He said. 'My friends! My space-trotting friends! We've lost touch.' 

Talliaferro said, 'Hello Villiers.' Villiers eyed him. 'Are you well?'

'Well enough.'

'And you two?'

Kaunas managed a weak smile and a murmur. Ryger snapped, 'All right, Villiers. What's up?'

'Ryger, the angry man,' said Villiers. 'How's Ceres?'

'It was doing well when I left. How's Earth?'

'You can see for yourself,' but Villiers tightened as he said that.

He went on, 'I am hoping that the reason all three of you have come to the Convention is to hear my paper day after tomorrow.'

'Your paper? What paper?' asked Talliaferro.

'I wrote you all about it. My method of mass transference.'

Ryger smiled with one corner of his mouth. 'Yes, you did. You didn't say anything about a paper, though, and I don't recall that you're listed as one of the speakers. I would have noticed it if you had been.'

'You're right. I'm not listed. Nor have I prepared an abstract for publication.'

Villiers had flushed and Talliaferro said soothingly, 'Take it easy, Villiers. You don't look well.' Villiers whirled on him, lips contorted. 'My heart's holding out, thank you.'

Kaunas said, 'Listen, Villiers, if you're not listed or abstracted-'

'You listen. I've waited ten years. You have the jobs in space and I have to teach school on Earth, but

I'm a better man than any of you or all of you.'

'Granted-' began Talliaferro.

'And I don't want your condescension, either. Mandel witnessed it. I suppose you've heard of Mandel. Well, he's chairman of the astronautics division at the Convention and I demonstrated mass transference for him. It was a crude device and it burned out after one use but- Are you listening?'

'We're listening,' said Ryger coldly. 'For what that counts.'

'He'll let me talk about it my way. You bet he will. No warning. No advertisement. I'm going to spring it at them like a bombshell. When I give them the fundamental relationships involved it will break up the