Equinox

'So what are we waiting for?' Jo said when it was over. 'Let's try the computer.'

Philip put the DVD in the drive and the screen lit up to display a short message:

Enter ' 1' and answer.

Philip hit the ' 1' key and a new line of text appeared:

LAURA, YOU LIKED IT THAT EVENING

Philip turned to look at Laura, an eyebrow raised. 'Well?'

'Well, what? What the hell is that supposed to mean?'

'It's the personal clue Charlie mentioned. The answer will be something obvious only to you.' 'Did you and Charlie. .?' Philip said. 'Oh, please.' 'Well, I just. .'

'He must be referring to New York,' Laura said. 'That's the only time I've seen him in the evening for twenty years. We went to Harry's Grill on West 34th Street.' She stopped for a moment and looked blankly at the screen, trying to recall the evening.

'Was there anything special about it?' Philip asked.

'The creme brulee was pretty amazing.'

'Let's try it,' Jo said.

Philip typed in 'creme brulee' and the screen went blank for a moment before a new message appeared.

WARM, BUT SORRY. JUST TWO TRIES LEFT

'Shit,' Philip exclaimed.

'What? I thought that was it,' Laura hissed and turned to her daughter.

Jo shrugged. 'Too easy, obviously. Then, pulling over a chair, she leaned across Philip. 'OK, we've got two more chances and that's it. We'd better take this a little more carefully.'

'But it's impossible,' Laura said. 'It could be anything.'

'Yeah, but it's a personal code, Mom, something you would know right away.'

'That's why I suggested "creme brulee", Jo. .'

'OK,' Philip said. 'Let's think. Charlie's clue is YOU ENJOYED IT THAT EVENING. What else could he mean? You sure he's even referring to the evening in New York?'

'How the hell would I know?' Laura could feel the frustration rising.

'I think you're on the right lines,' Jo said. 'Charlie says as much — warm — which must refer to the evening at the restaurant. But the code could be

"creme" or "brulee" or "cb". . anything.'

None of them spoke for a moment. Jo looked lost in thought. Laura ran her fingers through her hair and gazed at the screen.

'I think you're right,' Philip said, eventually. 'It could be anything, but Charlie gave you a clue after the first attempt. Maybe we need more information.'

'Yes, but that would give us just one last try.'

'Any better ideas?' Philip replied.

'Hang on,' Laura said suddenly. 'If we fail after three goes, can't we just reinsert the DVD and start again?'

'I doubt it. It'll wipe itself, I'm sure,' Jo said. 'Or self-destruct like in Mission Impossible? 'Oh, swell.'

'I think Dad's right, though. Without more information we could guess all night. Let's just try something and hope for the best.'

'Doesn't sound very scientific,' said Philip.

'How about just 'brulee'?' Jo suggested.

Laura shrugged. 'I guess.'

Philip typed in the word. After a moment a new message appeared.

STONE ME, LAURA. THIS IS SUPPOSED TO BE EASY FOR YOU! IT'S JUST FIVE LETTERS, BABE

'Damn it,' Laura exclaimed and exhaled through her teeth. Then suddenly she clapped her hands together. 'No, no, of course, that's it. .'

'What?'

'I remember now. We were just about to eat the creme brulee when the Rolling Stones' "Brown Sugar" came on the restaurant stereo. Charlie made a joke about the coincidence — creme brulee — brown sugar?' She leaned over Philip's shoulder and typed in five letters.

'Hang on, Laura,' Philip said, twisting round to face her. 'What're you going to put in?'

'Five letters, of course — Charlie says so — It has to be STONE, doesn't it? And besides, what is this all about anyway? What is the Order of the Black Sphinx after? What was Newton trying to get?' Before either of the others could say anything, Laura tapped in the five letters and hit 'enter'. This time the screen turned black. Then suddenly the word CONGRATULATIONS appeared.

Laura let out a deep sigh. She hit the 'enter' key again and the screen lit up with a new, more elaborate message comprising a line of words followed by a series of numbers:

BLACK, WHITE, YELLOW, RED, NEW YORK

3.5, 12,

67498763258997 86746496688598 97684795900082 08736047437980 73849096006064 87474877345985 47932768480950

Beneath these numbers was a block of text made up of hundreds of letters without a break.

'Is that it?' Philip asked and scrolled down, but there was nothing more.

'You know,' Jo said, 'your friend Charlie Tucker is something of a legend in the math department.' She gestured to Philip to let her take his seat.

Laura looked round at her. 'Well, he wasn't far wrong on the DVD when he called himself a genius.'

'Tell me about it. Professor Norrington, our Group Theory lecturer, remembers Charlie from when he was first teaching in Oxford. Norrington worked for the CIA and MI5 before he morphed into an academic — he was a code-breaker — and he claims that Charlie was the only mathematician he's ever met who could create codes even he, Norrington, could not crack.'

'Yes, but Charlie wanted us to get this information, didn't he?'

'Sure,' Jo replied, 'But it was in his blood — he couldn't just give it away.'

'Great,' Laura replied and walked over to the sofa.

'But luckily,' Jo retorted, 'you know another genius … and my first-year special subject is Group Theory — rather important in cracking codes.' She flexed her fingers and contemplated the screen. 'And I absolutely love a challenge.'

Chapter 33 Oxford: 30 March, early morning

'Mom. . Mom, wake up.'

Laura opened her eyes to see Jo's face hovering over her. She sat up quickly, putting her fingers to her temples. Sighing, she leaned back onto the cushions of the sofa.

'God, what time is it?'

'Four-fifteen.'

'Where's Philip?'

'Here.' Philip came into the living room carrying a tray. 'I think we all need this.' He put the coffees down on the low table in front of the sofa. 'Well, Jo does, anyway. You've slept through all the action.'

Laura was still half asleep. 'What are you talking about, Philip?'

Philip smiled at Jo. 'Our daughter has cracked Charlie's code.'

'Well, I've cracked

some

of it,' Jo said.

Suddenly Laura was wide awake. Grabbing one

of the coffees, she sat forward on the sofa. 'Start from the beginning, and take it slow,' she said.

Jo had a sheaf of papers in her hand. 'I tried all sorts of things to begin with, but nothing was happening. You have to experiment. Anyway, I started to think about what Charlie said about the ruby sphere. He mentioned the scytale and it suddenly occurred to me that this code he used on the DVD was also a scytale. Another clue came from the number 3.5 he wrote after the list of colours. Then there's the block of numbers,' she continued. 'Seven rows of fourteen apparently random integers. It seemed likely that there was a number combination there, some sequence that would be relevant. So I decided to print out the numbers. Then I made a tube of paper that was exactly 3.5 centimetres in diameter.'

'And the numbers fitted?'

'No.'

'What?'

'It wasn't as simple as I'd thought it would be. I was stumped. But then I looked again at the message. After the number 3.5 there was 12, New York. I'd assumed that New York referred to Charlie's visit in some way and that it might be relevant later.'

'But then,' Philip interrupted, 'Jo demonstrated true genius.'

Jo smiled at her father. 'Flattery will get you everywhere, Daddy. But, actually, it was obvious now I think about it. New York is a font. I had to print out the numbers using New York, size twelve.'