The bedside lamp was shining in Petries face. He waved Freya ahead and pulled on clothes, slipping his feet into shoes without tying the laces. He wondered if he was destined ever to sleep again, but the urgency in Freyas voice said there were other priorities.

Until he saw the Russian, Petrie had always a.s.sumed that 'foaming at the mouth, as a description of a man gone mad, was populist nonsense. But flecks of white frothy foam were dribbling out of the corners of Shtyrkovs mouth. He was in the main hall, arms flapping, an idiot grin lighting up his face. He was running from one chandelier to the next, shouting and laughing in Russian, staring up at them in adoration. Svetlana was standing at the foot of the stairs, long yellow nightdress hanging under her red robe and her face screwed up in distress.

The Russian saw Petrie, pointed to the chandeliers and called up in English, 'Look at the pretty lights! His eyes were starting to roll.

'How long has he been like this?

Svetlana said, 'I dont know. I heard him singing half an hour ago but didnt think it was anything at first. Ive been up for ten minutes. Ive tried to stop him but he just keeps going.

'h.e.l.l collapse, Freya said. 'n.o.body can keep that up.

Tears of happiness were welling from Shtyrkovs eyes; his voice was enraptured but he was gasping for breath. 'Arent they beautiful, Tom and Freya? Are we not in Paradise?

'Vash. Petrie stepped forward. 'Come to bed. But Shtyrkov giggled and ran off like a naughty child, wheezing and foaming.

'Where are the light switches? Petrie called back to Svetlana.

'Round here. She switched them off.

In the sudden pitch black, Shtyrkovs footsteps halted, as if he too had been switched off. Petrie moved in the direction of the mans rasping breath, took him by the arm, and led him back towards the stairs. Shtyrkov was trembling, and whimpering quietly.

'Temporal lobe damage. It affects perceptions.

'Are you sure, Freya?

'Not even fifty per cent sure. All I can say is that it fits the profile I got on the internet.

'Vashislav ran into the thick of the beam when it was. .h.i.tting the lake.

'Is it reversible, progressive or what? It was just after noon but Petrie was at breakfast: a biscuit, which he was dipping into his second coffee. He hadnt bothered to shave.

'I dont know. Some people say Van Gogh had temporal lobe epilepsy, that it maybe even accounts for the intensity of his paintings. Colours are brighter, everything is seen more vividly. And Vashislav seems to love glittering things.

'How can a particle beam do that? If it was disrupting cells it would surely have fried his whole brain.

Freya said, 'It usually needs a lesion, but there were thin, concentrated pencil beams in the flow. And maybe its more subtle than that. A powerful magnetic field applied to the brain can play tricks.

'If you say so.

'You dont understand, Tom, youre a creature of mid-lat.i.tude. Your body is synchronised with the rhythms of light. But in polar lat.i.tudes were more sensitive to the effects of strong geomagnetic disturbances. We dont understand how, but theres a clear connection between things like Russian mine accidents and strong magnetic disturbances up top. Its been established by the polar geophysics people at Murmansk. They do upper atmosphere.

Petrie said, 'The particles were surely non-magnetic, otherwise the underwater magnets would have distorted their paths.

'Unless they carried so much energy that not even forty thousand gauss could divert them, Freya suggested.

'Thats surely incredible, Petrie said.

'Its testable, Tom. The ionosphere is charged up. If you fired charged particles through the Earth youd create a short-circuit between ionosphere and ground. At the very least youd get disturbances in radio or radar. You might even get weird cloud effects through nucleation around the beam.

'What about Charlie and Svetlana? Petrie wondered.

'They were either on the periphery of the particle flow or they missed it altogether. I havent seen anything odd about them yet, Tom, have you?

'Theyre both odd. But what other symptoms might we see? a.s.suming its this temporal lobe thing.

'All sorts. Anxiety, visceral symptoms, feelings of fear or anger, destructive or aggressive behaviour, out-of-body experiences, you see tunnels, bright lights and so on. Sometimes you get an overwhelming sensation that theres someone near you. You might even see a face, and extreme character traits appear. Some people get religious hallucinations.

'At least Vash isnt claiming to be Jesus or something. Will you tell him what you suspect?

Freya said, 'Not until after the ET announcement. Lets not spoil his moment of glory.

'We should keep an eye on the other two.

Shtyrkov was last to appear, mid-afternoon. He showed no obvious after-effects, and made no mention of the trauma he had been through in the early hours. Petrie wondered if the Russian even remembered it. They settled themselves around a table in a bar next to the common room. Gibson stared greedily at a folder of papers Freya was holding.

Hanning said, 'Dr Popov gave me a very thorough briefing. I must say Im having difficulty taking it in.

Gibson ignored him; Freya was the focus of their attention. 'Friday afternoon, Freya. What have you got for us?

'Ive narrowed the source down to two possibles, depending on whether the particles came down through the lake from above, or up from below. Heres candidate number one. She spread a large image on the table.

There was an a.s.sortment of gasps from everyone. Petries mind began to race. Two blue, feathery arms spiralled out of a reddish-white nucleus. The arms were lined with dark lanes. One of them, with little outcrops striking off, extended as a long bridge to a smaller, outlying galaxy. 'M51, in Canes Venatici, not too many degrees from the north galactic pole. Its just below the Plough.

'M51? The Whirlpool galaxy? Gibsons tone was awed.

'The Whirlpool. A bright open-arm spiral, part of a little group of galaxies. Its over thirty million light years away. Specifically, the signal came from this region here. Freya used a pencil to circle a small area at the edge of the nucleus, where one of the spiral arms was just breaking away. 'Its rich in Population II stars, with lots of red and yellow dwarfs about ten billion years old. Twice the age of the Sun.

'But thats- 'If the signal came from here, Charlie, it set out thirty million years ago, long before h.o.m.o sapiens existed. Before there were even primates.

'Dont be daft, Gibson said. 'How could they signal us if we didnt even exist when they fired off their message? Anyway, no life forms could survive next to the nucleus of a galaxy. Whats your second candidate?

Freya spread out a second celestial image. The scientists gazed in bewilderment at a near-blank patch of sky. 'This is in a small constellation called Phoenix, in the southern sky. With the huge number of particles that flowed in I can place the source to sub-arcsecond accuracy. If the particles came up from below, they came from here. She pencilled a small circle of black emptiness. A faint star sat just outside the circle.

'Empty s.p.a.ce?

'This chart goes down to magnitude thirteen. But were looking at a very quiet bit of sky, well away from the Milky Way. In fact, almost in the direction of the south galactic pole.

'What does that mean?

'It means there are probably no more than a handful of stars within the sight cone. At a guess theyll be red and white dwarfs with very low luminosities, maybe a halo star or two. But basically were looking at an empty region of sky.

'What about this star? Gibson pointed to the little dot near the edge of Freyas pencilled circle.

'Nu Phoenicis. A late F dwarf, F8 V to be exact, fifty light years from us.

'Thats close. Can you rule it out?

'Not absolutely. But its unlikely.

'Excuse me, Hanning interrupted, 'but whats a late F dwarf?

'A Sun-like star, said Freya. 'Just slightly hotter. Its likely to have planets around it. But as I say, its just outside the error circle.

Gibson sighed and leaned back. 'So what do I tell the worlds press? And the Prime Minister and the Secretary General of the United Nations? That the signal came from empty s.p.a.ce?

'No, Freya said, 'you tell them that it came from the Whirlpool galaxy.

Hanning said, 'Forgive me, but I thought Lord Sangster had made it clear. You dont tell anyone about this without his clearance.

Gibson didnt bother to conceal his hostility. 'Youre here to observe, not lay down the law.

Hanning bristled, but said nothing.

Shtyrkov said, 'It has to be the Whirlpool.

Gibson shook his head. 'No. Its clearly the F star. I take your point about the error circle, Freya, but its not that far beyond the edge. The stars a dwarf, Sun-like. Its practically our next-door neighbour. And another thing: its at the right distance. Think about it. The first radio signals were leaked from the Earth a hundred years ago. As soon as the first radio waves from us reached them, fifty years ago, they knew we were here, knew we were technological. They immediately fired off their signal and it has just reached us now. It fits like a glove.

Shtyrkov said, 'Two intelligence-bearing systems that we know of, us and them, a mere fifty light years apart? The Galaxy would have to be crawling with life.

Gibsons thin lips crimped in annoyance. 'If thats what it takes.

Hanning cleared his throat. 'I have a little experience in these matters and I must say I agree with Dr Gibson. In politics, you cant approach a minister with ifs and buts. An air of certainty counts. You need to present a united front.

'Why? Petrie asked. 'Why not properly reflect the scientific uncertainties?

'It looks bad. It conveys an air of dithering, even incompetence. Given the bizarre nature of your claim, it might suggest to some that you are forgive me the victims of delusion or, worse, perpetrators of fraud.

'That is outrageous.

Hanning gave a cold smile. 'Welcome to the big bad world, Dr Petrie.

Gibson said, 'Thats what Ive been saying all along. Wed lose the drama, and we could even lose credibility. We must agree on the source of the signal.

'And if we cant?

'h.e.l.l, Tom, we can at least look as if we do. Were about to enter a political arena and sniping at the margins will just cause damage. We need a united front for the announcement, even if you have to put on an act for the occasion, okay? As team leader I expect you all to back me up.

'What, on the F star? Dismay and scorn mingled in Shtyrkovs voice.

'It seems to me the evidence is crystal clear on this. The signallers are on a small, Earth-like planet orbiting the star. Its either that, or the signal was sent to us thirty million years before we existed.

'We cant go public with the F star, Charlee. Its outside the error circle. Youll wreck our credibility.

'What else is there? The Whirlpool? Do you expect me to face the press and tell them its the Whirlpool galaxy thirty million light years away?

Svetlana, who had been sitting quietly throughout the discussion, finally broke her silence. Hesitantly, she said, 'Im sorry if this is a dumb question, but how could an alien civilisation possibly know about our underground lake?

17.

We Have a Problem 'I can explain that. Gibsons voice had a triumphant edge to it. 'Vashislav said it himself. Two civilisations so close together cant be a coincidence. Well, lets follow the logic. If hes right if Im right about the F star there must be a Galactic club out there. Millions, maybe billions, of civilisations talking to each other. That means a gigantic telephone network to go with it, particle flows crisscrossing everywhere. We just happened to drift across one of their lines of communication. The signal was just a lucky intercept.

Shtyrkov put his hands on top of his head and frowned in concentration for some seconds. Then, 'Charlee, here are two experiments for you. Number one: let a fly loose in a cathedral, blindfold yourself, and fire a pistol in any direction, preferably not at your head. Number two: put Lake Tatras out there somewhere in the Galaxy, even just halfway to the nearest star, and fire a signal in a random direction. Let me tell you this: youd stand a better chance of hitting the fly in the cathedral than the lake in the Galaxy.

Petrie was scribbling on paper. He looked up and said, 'Vashislav is right. The chances of a random interception, even with a big galactic club, everyone chattering to everyone else, are too slim for words.

Gibson said, 'Use your common sense. How can aliens know about an experiment in an underground lake?

Freya said, 'I can prove that they do.

The physicist gave Freya the floor with an ironic flourish.

She unconsciously flicked hair back over a shoulder and then itemised the points with her fingers. 'First. At the lat.i.tude of Lake Tatras were spinning at fourteen hundred kilometres an hour round the Earths axis. Second. The Earths...o...b..ting the Sun at thirty kilometres a second. Three. The Suns drifting at thirteen kilometres a second through our neighbouring stars, us along with it. And Four. Our neighbourhood, millions of stars in it, is...o...b..ting the centre of our Galaxy at two hundred kilometres a second.

Shtyrkov said, 'Of course, Freya. Seen from even a light year away, the lake isnt just a tiny target, its a fast-moving one.

Freya nodded. 'And the signal corrected for all these movements. It matched the lakes speed through s.p.a.ce with great precision.

'Whats your point? Gibson asked curtly.

Freya tapped her calculations. 'Admit to error, Charlie. Whoever fired that signal knew about your underground cave and targeted it.

'Oh yes, of course they did, Gibson said, his face flushing. 'Naturally they have telescopes that detect underground lakes from light years away and they even know weve set up an experiment under the water waiting for a signal. In fact, they knew we were going to set it up before we knew it ourselves and if you believe this M51 rubbish, they knew we were going to do that before we even existed!

'I dont claim to have any sort of background in science, said the Science Ministers envoy, 'but that would seem to be a problem.

'Indeed, Jeremy. And heres another problem. How do I face the worlds press on Monday and sell them a garbage tale like that without being carted off screaming to the nearest paddy wagon by men in white coats?

'Jeremy?

Petrie, in quiet conversation with Freya on a sofa, caught the unctuous tone of Gibsons voice. He glanced across. The physicist was leaning over Hanning, charm oozing out of his face and looking like a benevolent frog.

Hanning looked up from his scribbled notes in surprise. 'Yes, ah, Charlie?

'Time is short. The computer clocks were reading just after three oclock. 'I thought you might lend us a hand.

Hanning glanced down at his notes. 'Sangster is looking for a situation report at nine p.m. Still, I can spare some time. But be warned, I have no specialised knowledge, at least not in science.