Equinox

'Think of what?' said Philip.

'Well, it's obvious now. The sun, the moon and the planets all move across the sky, don't they?' Laura explained. 'The movement of the sun through the zodiac over the year gives meaning to the twelve star signs. Is that right, Tom?' He nodded. 'So,' she went on, 'during the first month of the year, the sun is seen in Capricorn, then in Aquarius, Pisces and so on. The sun enters Aries sometime late on — what? The twentieth or early on the twenty-first of March. Which is also around the date of the vernal equinox. After that it goes on to Taurus and all the others. But the planets and the moon can also enter and leave the star sign during the month.'

'But that doesn't happen all that often,' Tom added. 'The moon and the planets might be the other side of the sky all through the month, but sometimes they succeed each other into the star sign.'

'Yeah, b-' Jo began. Tom was there before her. 'I know what you're going to say, Jo. We've had this discussion before. You think it's all nonsense, but you have to differentiate between real astrology and the rubbish printed in women's magazines and

Sunday supplements. That stuff is based on nothing but the imagination of the hack who writes it. A properly trained astrologer deals with a far more complex set of ideas — a consideration of the effect of all the heavenly bodies, not just the sun.'

'The implication being,' Philip remarked, 'that these other heavenly bodies sometimes follow the sun into the sign of the zodiac and contribute to the astrological influence?'

'Exactly.'

'So it might well be that the moon went into Aries soon after Aries became the current sign and that's the link with the date and time of the second murder.'

'I would put money on it.'

'Yeah, but hold on. . You'll probably shoot me down in flames, but isn't there an elemental error here? These star signs were worked out — what? Ten thousand years ago?'

'Well, not quite that long,' Tom replied. 'Astrology began in Mesopotamia about 4,000 BC, I think.'

'OK, whatever! Six thousand years ago. The thing is, the constellations can't be the same as they were then because, relative to the Earth, the stars move quite a bit during a few thousand years. The constellations are not the same shape they were during ancient times and they are certainly not in the same places they were in then.'

'Well, actually, Jo, it's irrelevant,' Laura said.

'Why?'

'Because it only matters to tabloid astrologers.' Jo looked bewildered.

'Well, think about it. If everything has shuffled along one sign or more, it doesn't matter except to those who try to attach characteristics to people born under a particular sign. You know … if you're an Aquarius you're unconventional and have weak ankles. All that crap.'

'The celestial shift is something that real astrologers take into account. Laura's right,' Tom interjected.

'But then the vernal equinox is no longer in Aries.' Philip said.

'It doesn't matter unless you subscribe to Sunday-supplement astrology' Jo sighed. 'I guess.'

Laura grinned. 'It's OK, doll, you're just a mathematician.'

Jo laughed resignedly and took a sip of her soup.

'Anyway,' Philip added, 'our murderer appears to be inspired by astrology. We only need to concentrate on what he believes, not what we think of it all.'

'All right,' Laura said, putting her hands up. 'Let's get back to the real issue. Tom? You reckon it's likely the moon moved into Aries at the time of the second murder?'

'Well, it's easy to find out.' 'It is?'

'Just look it up at

almanac.com

I'm a subscriber.' 'Oh my God!' Jo said.

Tom was already walking over to a computer on the desk close to the sofa. 'Is this on-line?' he asked.

'Yeah. I've got ADSL,' Philip said and joined him at the terminal.

They brought up Google and Tom typed in almanac.com

It appeared a second later and he put in his personal ID. Then a new menu appeared. Along the left-hand column was a list of questions, with empty answer boxes.

Laura had followed them over, but Jo remained on the sofa.

'I just need to put in a few figures,' Tom said. 'It's a cool site, software that calculates the location of any planet and the moon at any time between now and the year 3000.' He hit the keyboard. 'OK, so, the moon, date: 21 March 2006.' He followed this with a few more numbers and answered a succession of questions before clicking on SEARCH.

The response came back with surprising speed.

'Cool,' Tom said.

'What is?' Laura asked, unable to make head or tail of the data.

'The moon entered Aries at 3.47 a.m. on 21 March.'

'That could be exactly the time of the second murder.' Philip was clearly impressed.

'Monroe was sure of the time?' Laura asked Philip.

'He said his forensic team believed that the murder had taken place between four and six hours before I got there. That was just before 8.30, so the murder must have been sometime between 2.30 and 4.30 a.m.'

'Tom, with this software you can track any of the planets as well as the moon?' Laura asked. 'Yes.'

'We need to find out if any of the planets are going to enter Aries, and when. Can we go through each one?'

'I can do better than that,' Tom replied. 'I can tell you the movements of all the planets as far into the future as you want.'

'Don't exaggerate, Thomas,' Jo said lightly. 'Only until the year AD 3000.'

Philip gave a snort of laughter, but Tom ignored her and tapped the keys, answering a succession of questions at the prompt. After a few moments he hit the SEARCH prompt again and pushed his chair back from the terminal. 'OK, do your stuff,' he said.

It took longer this time, but after perhaps twenty seconds a new screen filled with diagrams and lists of numbers appeared.

'What does it tell us?' Laura asked impatiently.

'I'm getting there’ Tom replied. He scrolled down, peering at the screen, then closed his eyes, lost in concentration. 'Jesus!'

'What?' Philip said.

'This is really something.'

'Will you please. .' Laura hissed.

'Sorry. Every so often you get a conjunction of planets-'

'When the planets line up?' Philip interrupted.

'Yeah, when two or more heavenly bodies — the moon and the planets — appear to line up as seen from the Earth. Getting a conjunction of two planets or a planet and the moon, say, happens quite often — that's called a three-body conjunction. Getting a four-body conjunction is rarer — it only happens every few years. A week from today, early on 31 March, at a few minutes after midnight to be precise, the moon and three planets will be almost perfectly arranged to form a five-body conjunction with the sun. That is so rare it's only happened maybe ten times during the past thousand years or so.'

Laura was the first to react. 'So that means three planets are going to enter Aries during the course of the next few days?'

'Yep.'

'You can find out which?'

'I already have,' Tom replied and pointed to the screen.

'Venus, Mars and Jupiter, in that order.' 'When?'

'Jupiter, just after midnight on 31 March; Mars, a few hours earlier, the evening of 30 March; and Venus … let me see,' he muttered, scrolling down. 'Venus passes into Aries tonight, at eight minutes past nine.'

Chapter 14

Cambridge: the evening of 10 August 1690

John Wickins had come up to Cambridge in 1663 and now it was as familiar to him as his mother's face. He knew every turn of every lane, every plant and every weed that sprang forth from the paving stones on his regular walks. He knew every college Fellow and each townsman who crossed his path. He had enjoyed many of the same routines for almost three decades: he bought his books at the same shop, filled his inkwell from the same stationer's, had his clothes tailored in precisely the same way by the same, now elderly tailor, and he purchased his snuff from the same dealer who had first procured it for him twenty or more years earlier. But now he was leaving, and the place no longer seemed the same.