Svetlana pointed to a far corner of the lake. ‘Can you zoom into that?’
Petrie obliged.
‘Now go back to the original trajectories, not the points.’
A cluster of parallel lines appeared.
‘Now turn them. Look at the lines face-on.’
The lines shrank, turned back into points.
‘Right. Absolutely straight, no curvature. In that corner, Tom, about twenty metres under the water, we have a dipole magnet that weighs half a ton and gives us forty thousand gauss. If we swam anywhere near it with anything metal we’d be pulled under. If the particles were charged their tracks would bend near the magnet.’
‘And they don’t.’
‘Exactly, so they’re not cosmic rays. Cosmic rays are charged, they’d be deflected. We have half a dozen magnets like that under the water and we can do more checks if you like.’
‘Okay, Svetlana, if they’re not cosmic rays, what then?’
‘This time yesterday I’d have called them dark matter.’
‘And today?’
‘A neutral particle penetrating half a mile of rock? Unknown.’
‘A vast surge of them,’ Gibson reminded her. ‘Double unknown.’
‘Unknown to us,’ Svetlana said.
‘Which safely rules out some clown playing games with satellites.’ Petrie was having trouble holding his head upright.
Freya said, ‘The particles could have penetrated the lake from below.’
‘You mean they came clean through the Earth?’ Gibson asked.
‘Or from some accelerator on the surface of the Earth. Therefore it still might be a trick.’ Svetlana was saying the words with every sign of disbelieving them.
‘Total fantasy,’ Shtyrkov said. ‘A flux of this magnitude is thousands of years in the future even if we were dealing with a known particle type, which we’re not.’ He struggled out of his chair. ‘Ladies and gentlemen, we can securely eliminate both a natural source and a human one. Tom is right.’
‘You were right, Vash,’ said Petrie loyally. ‘Your intuition saw this.’
Shtyrkov brushed the compliment aside. ‘Lunacy has its compensations.’
‘If that was just their opener, what about the rest of the message?’ Charlie asked, his voice greedy. ‘What’s in it?’
Petrie said, ‘If I don’t get some sleep I’ll crack up.’
‘I don’t care.’ Gibson didn’t seem to be joking. He was jiggling around excitedly.
‘Ignore him, Tom. Go to bed,’ Vashislav ordered. ‘We’ll play around with this. And, Tom — congratulations.’
Unexpectedly, Freya gave Petrie a hug. ‘A signal from another world. This is the dream of poets.’
Petrie hadn’t thought of it that way; but he thought the Norwegian woman had a terrific smile.
Svetlana said, ‘I’ll make you my great-aunt’s pyzy when you get up.’
‘The cleaners!’ Gibson was suddenly horror-struck. ‘They mustn’t see this. They come at eight.’
‘Okay, Charlee, don’t panic. We’ll keep the cleaning ladies out of here. We don’t want them to look at the screen and say, “Hey, here’s a picture of DNA sent by extraterrestrials.”’
Petrie was wakened by sunshine in his eyes. His watch said 3.30 p.m. and his bladder was bursting. He relieved himself, stared at the unshaven hobo staring back at him out of the mirror. He ran a shower, shaving in the flow of warm water. Then he dried himself and rummaged in his holdall. He put on jeans and a white T-shirt emblazoned with a picture of pieces on a chessboard; to the cognoscenti, it showed the board at the moment the computer Deep Blue finally crushed Kasparov. When asked, he liked to explain that it symbolised the triumph of the machine over the human spirit; the reaction was always fun.
Svetlana was standing by the stairs on the floor below. She beckoned, and Petrie followed her along the corridor and into the refectory. A single place had been set with what looked like Hapsburg silverware. The pyzy turned out to be small, hot dumplings served with sausages. They were spicy and delicious, and had a warming effect which seemed to go beyond their heat capacity.
‘I think Freya has found something,’ she said.
Petrie washed down the last dumpling with hot tea.
‘Come and see.’ She extended her hand and Petrie took it; it was thin and warm. She led him to the corridor, down the stairs and into the administrator’s office.
‘Ah, the Kraken awakes,’ Gibson said obscurely. ‘Come and see what Freya has found.’
Freya was at a terminal. There was an empty chair next to her and she patted it. Gibson breathed garlic over them. Shtyrkov, taking up an armchair, waved at Petrie without looking up from a wodge of papers. Svetlana settled down at a terminal on another desk.
Petrie looked at the screen: there was what seemed to be a white shoebox traversed by parallel red lines. ‘Tom, this is near the beginning of the signal.’
‘Okay.’
She tapped at the keyboard. ‘And this is a slice near the middle.’ A set of parallel blue lines appeared. ‘And here we have a slice from near the end of the transmission.’ A third set of lines, in green. Petrie shook his head.
‘Look closely.’
‘I don’t see anything.’
‘Okay. Now let me take the average direction of the red lines, and then the blue ones, finally the green.’ She tapped on the keyboard.
‘Ha!’ Petrie exclaimed in delight. Three large circles — red, blue and green — showed on the screen, red to the left and green to the right.
‘Exactly.’ Freya was unable to keep a touch of pride out of her voice. ‘The direction of the source changed with time.’
‘The source was moving?’
‘No, we were. The lines stayed parallel in space while the Earth was turning. The rate and direction match the Earth’s rotation exactly.’
Shtyrkov called over from his armchair. ‘So, we can rule out a satellite as a source, or anything on the Earth. Whatever the source, it’s in deep space.’
Freya agreed. ‘Deep space it is.’
‘And you now have the position of the source in the sky?’
‘Two possible positions, depending on whether the signal came down or up through the lake.’
‘And?’
‘Give me a chance, Tom, I’ve only just discovered this. I need to carry out an error analysis to shrink these big circles to tiny spots. When I’ve done that I’ll download star charts and catalogues and see what we’ve got.’
‘Well, get on with it,’ Gibson said impatiently.
Freya turned, smiled sweetly at Gibson and said, ‘Dra til helvete.’ Then she returned to the keyboard.
Petrie turned to Gibson. ‘Okay. We’re all agreed that the signature is extraterrestrial, and the source is intelligent. What now?’
Gibson pulled up a chair and picked up papers from a desk. ‘There’s an outfit called the Institute for Aeronautics and Astronautics and they’ve set up a protocol. Vashislav’s going through the small print now.’
‘Let’s hear it.’
Gibson waved the papers. A slightly pompous tone was creeping into his voice. He read: ‘“Declaration of principles concerning activities following the detection of ET.” Principle number one. “Any individual, public or private research institution, or governmental agency that believes it has detected a signal from or other evidence of extraterrestrial intelligence should seek to verify that the most plausible explanation for the evidence is the existence of extraterrestrial intelligence rather than some other natural phenomenon or anthropogenic phenomenon before making any public announcement.”’
‘That’s why I’m here,’ Petrie proposed. ‘Okay, so Freya and I have confirmed it.’
‘And you can exclude any possibility of error?’ Gibson said in an interrogatory tone. ‘With such confidence that you are prepared to face the world and say, “These people have discovered ET”?’