Equinox

'Well, we do have a very good numismatics section. I could take you downstairs and get you started. I think we can forget about form-filling for today'

As Lightman stood up, he seemed to notice for the first time what she was wearing around her neck. 'Good gracious, Laura. That's the pendant I gave you. . when was that, now?'

It was an opal on a delicate silver chain. Laura had put it on this morning without consciously realising that it was the one Lightman had given her. 'When I was a student,' Laura said. 'Must have been

1983. Long time ago. I wear it almost every day, though.'

'Did I ever tell you that was my daughter's birth-stone?'

'No, you didn't.' 'Right, well. Let's go.'

Downstairs in the main hall of the library Laura followed Lightman along the parquet-floored walkways that transected the room between rows of vast oak bookcases. They crossed the hall and, at the far end, Lightman led the way through a tall doorway. Turning left, they walked along a corridor, through an archway to the right and into another room, a smaller version of the main hall. Halfway along this room's walkway Lightman turned right again and stopped at a set of bookcases against the wall. In front of them stood a large table with a computer on top of it. They were alone in this part of the library.

'This is the section,' Lightman said and scanned the shelves. 'I think you'll find everything you're after here, Laura. If you need anything, Mrs Sitwell is just around the corner.' He pointed to the far end of the room. 'She knows this section like the back of her hand. But if you want any more information from me, don't hesitate. I have some bureaucratic nonsense to sort out upstairs.' Leaning forward, he pecked her on the cheek. 'Come and see me before you go.'

Laura sat down and looked up at the great array of books. She suddenly felt a pang of guilt over spinning a yarn for the old man. But, she reasoned, she couldn't have done much else.

She had no clear idea exactly what she was looking for and plucked out a book entitled Ancient Coins , published by Oxford University Press. Then she pulled out the print that Philip had run off for her and the notebook containing her rough sketch of the other side of the coin.

Within a few moments Laura had learned that although early coinage is known as a Greek phenomenon, the earliest known coins were actually from the Lycian region of Asia Minor, found beneath a sixth-century BC temple of Artemis. The coins left at the murder scenes looked like they might have come out of Egypt, but this book mentioned nothing about early coins from that part of the world. She took down another volume. Coins of Antiquity by Luther Neumann.

Close to the start it offered a couple of speculative paragraphs on Egyptian coins and currency from the period after Egypt had been absorbed into the Roman Empire. It didn't seem that important, though, and the author offered little more than a brief account of how some of the earliest coins in Egypt may have been designed by alchemists and occultists who were obsessed with gold and other precious metals. These men had been court magicians for some of the Pharaohs.

Laura was about to return the book to the shelf when an odd thought struck her. It was something that James had said. 'The opal was my daughter's birthstone,' she repeated Lightman's words out loud, and she opened the book again. Turning to the page she had just read, the word 'alchemist' jumped out at her.

Feeling her pulse quicken, she pulled the notebook over, flipped the page and wrote down: 'Alchemist, Magician, Ancient Egyptians, Birthstones, Gold and Silver' — followed by four large question marks.

Returning Coins of Antiquity and Ancient Coins to the shelves, Laura ran a check through the computerised catalogue, looking for anything that might deal with the very earliest coins. She found just one title, a Victorian book called Lost Numismatics by a Professor Samuel Cohen. Then she ran another search for 'Egyptian Alchemists'. Apart from a clutch of modern sensationalist titles that she decided she couldn't trust, this again offered only one book of original scholarship, another ridiculously obscure Victorian tome: The Black Arts of the Pharaohs , written by one Erasmus Fairbrook-Dale.

Laura was starting to enjoy herself. It reminded her of college days: fond memories of afternoons spent in rooms just like this one following leads that took her from one concept to another, a winding path through an intellectual maze. Maybe, she thought as she opened Lost Numismatics and turned the huge pages with exaggerated care, this was what had first inspired her to work in crime journalism, the thrill of sniffing out the clues to a mystery. If that was true, it had also led her inexorably onward to become a thriller writer.

Then she saw it: in the centre of page nine, a picture of two discs, the dual aspects of a coin. The first disc showed an image of five women in long flowing robes holding a large deep bowl aloft at arm's length. Next to that, the other side of the same coin, was the head of a young Pharaoh. The face was slightly different to the one in Philip's photograph, but everything else about the coin was identical. With growing excitement she read the text printed beneath the pair of pictures:

Known as the Arkhanon coins (c. 400

BC

, Napata region), these were handmade by the court magicians of King Alara. Each contains images reflecting the Ancient Egyptian concern with the unity of all things, the holistic pairing of complimentary elements. This example is a gold coin and it carries the image of a quintet of women holding a representation of the sun. Two other very similar Arkhanon coins have been found at the same site: a silver coin bearing the image of five women holding a bowl containing an image of the moon, and a third made from iron with another sphere (supposed by some authorities to be the planet Mars) held aloft by another quintet of robed female figures.

'Christ,' Laura said aloud. 'Well, clever me.' Then turning to the second Victorian book, The Black Arts of the Pharaohs , she flicked through the pages, reading random sections until she reached a chapter entitled: 'The Birth of Holism'.

Three hours later, Laura emerged into bright afternoon sunshine that burst through low black clouds. The road outside the library was glistening from very recent rain and a faint rainbow shimmered over the Radcliffe Camera, but Laura was almost completely oblivious to the sight. She was lost in an ancient world of magic and occultism, thrilled that she might just have stumbled on a crucial clue.

Chapter 12

The Acolyte was proud of the work that he had done. It came as the fulfilment of a long-cherished dream. He was working for one of the greatest men alive, doing work that made a difference, work that had meaning, purpose. And he was part of the great plan, the Great Work as it had once been called hundreds of years before his time.

He had trained for many years so that he might complete the tasks for which he was now responsible. That training had been gruelling. He had studied at the best medical schools, practised in the operating theatres of three internationally respected hospitals, roved through disciplines and acquired many skills while honing his considerable natural talents. He had studied cryogenics, psychology and mathematics as well as pursuing occult studies that included numerology, astrology and alchemy.

He pulled his inconspicuous black Toyota into a vacant visitors' space in the car park of Somerville College, Oxford and stepped out onto the gravel. The soles of his handmade black brogues crunched on the stones. He brushed imaginary flecks of dust from the front of his immaculate Cerruti suit, smoothed back a few strands of hair above his ears, straightened his already perfectly aligned silk Hermes tie and studied his reflection in the rear nearside car window before walking towards the main quad of the college.

The Acolyte glanced at his Patek Philippe. It was almost three o'clock. Samantha Thurow, a third-year history and politics undergraduate, would, he knew, be emerging from Staircase 7 at any moment. From the second she appeared here until 9.08 p.m. precisely he would keep close track of her movements. In a broad sense, he already knew what those movements should be: he had wired her room in a student house in Summertown just north of the city centre and he had tapped her phone.

As he recalled these facts and began to feel the first tingle of sweet anticipation, he saw Samantha walk from the darkness of the entrance of Staircase 7. She was talking to another student, a short Asian girl. Samantha