Mr Wud was something that she and her father had invented. At least, they thought they'd invented him. He had come about, indirectly, through Sarah's mother. Zok Becker believed in many things. Well, maybe not believed in, as such, but wasn't going to take any chances where they were concerned. Astrology? Well, yes, of course it's nonsense, but there's no harm in knowing what it says and it's surprising how often it seems to be very accurate. Feng shui? Just common sense, of course, but windchimes look pretty and make a nice sound so why not have them anyway? And if a certain type of bird happens to fly across your path, which some people might think could be unlucky, then there are rhymes to say and small hand gestures to make which surely can't do any harm.

As often within families, Zok had inherited her superstitions from her grandmother, rather than her mother, a hardheaded ex-publisher who believed primarily in jogging. Michael Becker had no truck with such spells and signs, and neither did his daughter. Mr Wud had come about as a private joke between them, a response to the superstition that most drove Michael Becker up the wall. Whenever anyone in the family said anything that could — to even the very mildest of degrees — be said to be tempting fate, then Zok Becker would immediately follow it by saying 'Knock on wood,' as swiftly and unconsciously as you might say 'Bless you' after someone sneezes. If someone said 'I'll never end up like that,' she'd say 'Knock on wood' and rap the table with her knuckles. If they said 'My father's in good health,' she would say it — increasingly quietly, as she became aware that her husband found the habit wildly irritating — but she would say it. She would even say it, and this was the kind of occasion that made her husband want to gnaw chunks out of the piano, if someone said something like, 'I've never broken my leg.' Michael Becker would point out that this was a factual statement, and not flipping the bird at the fates. It was merely a recital of a true condition of the world, and hedging it off with a superstitious mantra was ridiculous. You wouldn't, he'd patiently observe, say 'Two plus two equals four — knock on wood,' and so why use the expression after any other kind of fact? It was an explicable habit, and borderline bearable, when used after a statement that showed hubris in the face of the world's potential to hurt. But if it was just a goddamned fact…

Zok would listen to this, as she had many times before. She would then point out that it was a well-established tradition in many parts of the world — in England and Australia, for example, where they would say 'Touch wood' in similar circumstances — and that there might be some basis to it because trees had power, and anyway it didn't do any harm. And Michael would nod, walk quietly out of the room, and go gnaw chunks out of the piano.

Sarah sided with her father on the subject, and over the years they'd developed the character of Nokkon Wud, an evil sprite, probably Scandinavian in nature, whose sole job was to listen for people challenging the fates by rashly making factual observations. He would then swoop invisibly into their homes in the dead of night, and give their lives a stir for the worse. You'd better not feel lucky when Nokkon was around, because he'd know, and punish you for it.

Over the years this had evolved into their parting routine, in which they genially wished some ill upon each other so that Nokkon would hear and know he wasn't required in their lives. It had also proved useful when Sarah's sister, Melanie, had started having nightmares a year back. At Sarah's suggestion, Michael had told her this was Nokkon Wud at work, flying past the bed, sniffing out for people to harm. All Melanie had to do was recite a little rhyme — which her father spent a long time writing, with more redrafts than most of the scripts through which he earned his living — and Nokkon Wud would know that he wasn't needed there and go bother someone else. Melanie tried this solution, dubiously at first, but was soon saying it before she went to bed every night — and in time the bad dreams went away and it mattered less whether her cupboard doors were sealed absolutely tight. Her mother didn't really approve of the joke, and never personally invoked him, but would sometimes smile when Nokkon was mentioned. He explained things about the world, and was now enshrined in Dark Shift as one of the recurrent minor demons ganging up on the heroine. Her father's partner had questioned the idea, with much questioning of skill sets and back story, but Michael kept it in anyhow.

As Sarah lay beneath the floorboards in a house inhabited by a madman, she was wondering if her mother hadn't been right after all. Maybe there was such a monster, such a spirit. And maybe he had known they had been mocking him, had been too complacent. And maybe this had made him angry. And maybe it was he who had come for her, and he came in darkness to see her now because he had no face beneath the mask he had shown to capture her.

Sarah lay still, her eyes open wide.

The paper, which was entitled 'The Krüniger Plot and Mittel-Baxter Society', detailed an archaeological investigation that had recently taken place in an area of Germany with which the man was unfamiliar. He had found it in his atlas, and established it was too distant from any of his contacts for them to be able to provide any on-the-spot observations, and so he was restricted to the information in the paper.

A graveyard had been discovered not far from the remains of a Neolithic settlement. Carbon dating of the skeletons, together with corollary evidence from personal items found within some of the graves, had allowed the site to be dated to the latter part of the eighth millennium B.C. Ten thousand years ago. The man sat for a while, savouring the thought, summoning up an image of this cross-section of time. Before any now-recognizable language had been spoken, long before even the Pyramids had been built — unless one believed the claims of the New Age archaeologists with their selective evidence-gathering and flimsy projections — these people had lived and died and been laid in the earth, had made love and eaten and shat their waste on the ground. The man sipped a little of his coffee, being careful to replace the cup on the side table so that it was only just balanced. Then he read on.

There were twenty-five sets of remains. Women of up to young middle age, children, a few men in their late teens or early twenties, and one man of more advanced years. Thorough appendices detailed the condition of each of the skeletons, and outlined the techniques that had been used both to age them and establish the dietary and environmental conditions within which they had lived. The authors of the paper remarked how the skeletons had been laid in a grid, an organized system of burial observed in no other sites in that part of Europe at the time. They provided diagrams demonstrating how the orientation of the grid was in accordance with what was understood of the period's interest in the summer and winter solstices, thankfully avoiding a digression into primitive astronomy. They instead produced a series of arguments to show that this arrangement provided further evidence for a proposition to which they had been committed for some years: that this particular area of Germany had been host to a hybridized form of social organization that they termed Mittel-Baxter Society (for such were the authors' names), a sporadic and localized culture of very minor academic interest and negligible long-term significance.

The man read the paper carefully to the end, and then worked steadily through the appendices. After reading the reports on the skeletons of the other deceased, nodding occasionally at what he regarded as perfectly well-argued conclusions, he came to the section regarding the older man who had been found at the site. The position of his skeleton — at the exact centre of a five-by-five grid — suggested that he had been the first to be buried in this plot, and the authors argued compellingly that this implied that the man had been a person of importance within the nearby village. It was also deduced that he had been born in a different part of the country, as bilateral pitting in the interior of his eye sockets — a condition known as cribra orbitalia — suggested that his diet had been deficient in iron for much of his life. The amount of iron in vegetation is determined by the geological qualities of the soil in which it grows, and its absorption affected by the amount of lead present: people from different areas will therefore show marked variations in the condition. Cross sections taken from the man's teeth, and subsequent analysis of the levels of lead and strontium isotopes, had enabled them to link him to an area over two hundred and fifty miles away. In an aside it was observed that a lesion on his skull bore witness to a blow to the head that had not proved fatal — as the damage it had caused to the bone tissue was long-healed prior to the man's eventual demise. They speculated that this might have been a result of a battle or struggle for power, and that this proved he had lived a long and vibrant life. A man who, the authors provokingly speculated, might even have been personally responsible for bringing Mittel-Baxter culture into a previously uncivilized and backwoods area, and whose local significance had been enshrined in the manner of his burial. The man read this section for a second time, and then closed the paper on his lap. He was very pleased. This was the best yet, much better and far, far older than even the seven ancient burials discovered together high on the Nazca plain at Cahuachi, each with fossilized excrement in their mouths. He felt pity for Mittel and Baxter, though he supposed it unlikely that the full stupidity of their conclusions would ever be brought to light. Perhaps the paper might even help maintain their tenure at the godforsaken midwestern university for which they toiled. He could, he supposed, get in touch with them and put them in the picture. He doubted that he would be believed, however, even though the truth of the matter was there for those who had eyes to see. Archaeologists were worse than most when it came to judging evidence on the basis of their pre-existing suppositions. It didn't matter whether they were flair players like Hancock and Baigent, or journeymen like Klaus Mittel and George Baxter: they all saw what they wanted to see. The traditionalists could only ever see ceremonial walkways, the New Agers their alien landing strips — however absurd each idea was in individual circumstances. Some of the time each was correct, but they'd never know when — because in their minds they were right all the time. Only if you were prepared to examine the evidence dispassionately could you reliably divine the truth.