It appeared to Umber to be an aerial photograph of some desert landscape, buttes and mesas widely spaced and varied by what looked like craters and a couple of strange conical formations. Most striking of all, however, was a mound close to the centre of the picture so contoured that it looked for all the world like a relief depiction of a human face.
'Ever seen this before, David?' Nevinson asked.
'I don't think so, no.'
'What do you suppose you're looking at?'
'The desert somewhere. Egypt, maybe.'
'Why Egypt?'
'The formations… don't look completely natural. And this…' He pointed to the face. 'I don't know. I suppose it reminds me of the Great Sphinx in some way.'
'Interesting you should say that. In fact, this is a photograph of the surface of Mars taken by the Voyager One orbiter in July 1976. It's a site in the northern hemisphere known as the Cydonia complex.'
'Really?'
'Really and truly.'
'So, these… shapes… are just freaks of nature.' Sharp had warned him about Nevinson's Martian fixation, but he had not expected it to exhibit itself so swiftly. 'Unless you're going to tell me they're not natural.'
'You said as much yourself.'
'I said they didn't look natural. That's not the same thing. This… face… could be an optical illusion caused by… the angle of the sun.'
'What about this?' Nevinson pointed to a large circular rimmed depression near the right-hand edge of the photograph.
'A crater.'
'And this?' Nevinson's finger moved to one of the conical mounds, below and slightly to the left of the crater.
'An extinct volcano?'
'NASA would be proud of you.'
'Percy, what has this to do with -'
'Avebury? Simple. It is Avebury. What you call a crater and an extinct volcano are perfectly scaled representations of the stone circle at Avebury and the artificial hill at Silbury. Or vice versa. They are precisely proportionate and have the same geometric relationship. Trace a line due north from the centres of the volcano and Silbury Hill and you'll find that the centres of the crater and the Avebury circle are offset by exactly the same angle. Nineteen point four seven degrees. Does that ring any bells? 1947?'
'The Roswell incident.' Umber's heart sank. This was worse than he had first thought. Far worse.
'July's been a busy month over the years. Roswell. Apollo Eleven. Voyager One. And our own strange experience.'
Alien abduction. That was it, then. Nevinson's theory of choice to explain two men in a white van, one missing girl and one dead one. Umber sighed. 'Do you really believe this, Percy?'
'I've been compelled to. The evidence is overwhelming.'
'So… Tamsin was kidnapped by Martians?'
'Certainly not.' Nevinson frowned pityingly at him. 'Have you taken leave of your senses?'
Umber smiled grimly. 'I'm not sure.'
'Wessex is an encoded landscape, David. That's what you have to understand. Avebury. Silbury. Stonehenge. Woodhenge. The long barrows. The linking avenues. There're repositories of information – of ancient secrets. But not everybody wants those secrets to be uncovered.' Nevinson's voice dropped to a whisper. 'By the summer of 1981, I'd gone a long way towards cracking the code. I notified the authorities of my preliminary conclusions. I thought it my duty to do so. That was a mistake. Sadly, I fear Tamsin and Miranda Hall paid the penalty for my mistake.'
'How do you figure that out?'
'I believe the incident was staged to demonstrate to me that innocent people would suffer if I continued with my researches. Of course, no-one was intended to die. The driver of the van simply panicked. But Miranda's death complicated matters. I believe it's the reason why Tamsin was never returned.'
'What became of her, then?'
'I don't know. I imagine she's alive and well somewhere, with no conscious memory of what occurred that day. She was only two years old, after all.'
'Did you tell Sharp any of this at the time?'
'I hinted at it. But I was left in no doubt that he'd been warned off by the powers that be. Hence the need for us to meet… a deux.'
'I see.'
'I suspect you've been manoeuvred into accepting his assistance. His role is to ensure you don't find what you're looking for. And, before you ask, I'm afraid I can't disclose what I've learned from my study of the henges. Naturally, I've continued to work on the subject since 1981. But to share my findings with others would only be to endanger them.'
'Of course.'
'I strongly advise you to abandon your investigation. If you must persist, do so alone. But be aware of the risks you'll be running. They're considerable. Although…'
Nevinson's voice trailed off into a silence Umber felt no inclination to break. The man was mad. That was clear. Not barking. But mad nonetheless. Yet his madness at least ruled him out as Sharp's correspondent. His obsession left no room for Junian diversions. Even Percy Nevinson could not suppose that Junius was a Martian.
'I don't really need to tell you, do I?' Nevinson appeared disappointed that some prompting was required. 'Your wife's sad example is a salutary one.'
'What do you mean?'
'Neither of us believes she died accidentally, do we? Or by her own hand. She must have strayed too close to the truth. How close, I assume you don't know, otherwise you wouldn't be here. The desire to avenge her is doubtless considerable, but -'
Umber stood up suddenly, pushing his chair back against the vacant table behind him with a thump. It stopped Nevinson in mid-sentence. He goggled up at Umber in surprise.
'What's wrong?'
'Nothing's wrong. I'm leaving. That's all.' Umber plucked a fiver out of his wallet and tossed it onto the table. 'Not sure that'll stretch to the cake, but I'll have to leave you to settle up, I'm afraid.'
'But… we haven't finished.'
'Oh yes, we have.' Umber smiled stiffly. 'I've heard enough.'
Umber needed a walk to calm himself before reporting back to Sharp. In the course of it, he began to suspect that Sharp would criticize him for failing to confine Nevinson to practical issues. But there it was. The man was impossible. He was also, Umber felt sure, irrelevant.
As it turned out, Umber had more time to prepare his excuses than he thought. When he reached the Ivy House, he was handed a note from Sharp. Have gone to Devizes. Back later. As messages went, it was less than illuminating.
Wiltshire Constabulary Headquarters was in Devizes. That fact, once quarried from Umber's memory, lodged stubbornly at the fore of his thoughts as he awaited Sharp's return. Eventually, he quit the hotel in search of dinner. On his way back from the restaurant he wandered into the Green Dragon, a quiet, smoky pub, where he sat by the fire with a pint and did his level best not to imagine what conspiracy theories Nevinson might concoct if he knew of Sharp's unannounced journey. This exercise in mental discipline was itself partly designed to prevent his dwelling on Nevinson's absurd notion that Sally had been murdered. Down that road, Umber feared, lay his own brand of madness.
At some point he remembered, to his irritation, a question he had meant to put to Nevinson. What had he wanted to show Jeremy Hall at the Adam and Eve stones that day in July 1981? It was a magnifying glass Umber had seen flash in the sunlight. He knew that because he had noticed it clutched in Nevinson's hand as they stood together at the roadside. But what had he been using the glass for? What had he been looking at? Marks on one of the stones that he believed were Martian runes, in all likelihood, but-
'There you are, Umber.' George Sharp loomed suddenly into view. 'This is the third pub I've tried. Want a half in there?'
Taken aback as much by Sharp's unwonted jollity as his unheralded arrival, Umber mumbled his thanks and struggled to order his thoughts while Sharp bought the drinks. The pub was far from busy, however. Sharp was back within a couple of minutes.