The Moses Stone

24

Angela Lewis stepped into the arrivals hall at Casablanca's Mohammed V Airport, looked round and spotted Bronson almost immediately. He was a couple of inches taller than most of the locals milling about, but what made him stand out was his obvious European dress – grey slacks, white shirt and light-coloured jacket – and comparatively pale face under his slightly unruly thatch of black hair. That, and his undeniable good looks, which always gave Angela a visceral thrill when she saw him.

A sudden feeling of relief flooded through her. She'd known he'd be there, because he'd told her so, and her exhusband was nothing if not reliable, but there'd still been a slight nagging doubt at the back of her mind. Her biggest fear was that something might have happened to him, something that would leave her stranded in Casablanca by herself, and that was a prospect she'd been dreading.

She smiled broadly and started threading her way through the crowds towards him. Bronson spotted her approaching and gave a wave. Then he was right in front of her, his strong arms pulling her unresisting body towards him. For a few moments they hugged, then she stepped back.

'Good flight?' he asked, taking her suitcase and laptop bag.

'Pretty average,' Angela replied, swallowing her pleasure at seeing him again. 'Not enough leg-room, as usual, and the in-flight meal was rubbish. I'm starving.'

'That we can rectify. The car's outside.'

Twenty minutes later they were sitting in a restaurant on the southern outskirts of Casablanca, watching the waiter place a large dish of lamb tajine on the table in front of them.

The restaurant was under half full, but Bronson had been adamant that he didn't want one of the tables by the windows, or close to the door. Instead, he had chosen one right at the back, with a solid wall behind it. And although Angela preferred to sit where she could see the other diners – she'd always enjoyed people-watching – Bronson had insisted on taking the seat that offered a clear view of the door so he could see anyone coming in.

'You're worried about this, aren't you?' she asked.

'Damn right I am. I don't like what's been happening here in Morocco or in London,' Bronson said. 'Something's going on, and the people involved seem to be completely ruthless, so I'm watching our backs. I don't think anyone could have followed us here, but I'm not taking any chances. Now, tell me what happened at your apartment.'

'Just a second.' Angela's mobile had begun ringing inside her handbag, and she quickly fished it out and answered it.

'Thanks,' she said, after a few moments. 'I knew about it. Did the police turn up? I called them when I left the flat.'

There was another pause as the caller explained something to her.

'Good. Thanks again, May. Listen, I'm out of the country for a few days, so could you get in a locksmith, please? I'll settle up with you when I get back.'

Angela closed her mobile and looked at Bronson. 'That was my neighbour in Ealing,' she said. 'No surprises, except that the police did turn up – I wasn't sure they'd bother. My apartment's been thoroughly trashed. Oddly enough, it doesn't look like much, or maybe anything, was taken. May said the TV and stereo are still there, but every drawer and cupboard has been emptied.'

'That sounds familiar,' Bronson said. 'So you scrambled down the fire escape?'

Angela swallowed, and when she spoke again her voice was slightly unsteady. 'Yes, that's right. All I had time to do was grab my handbag and laptop, and then I just ran for it. One of the men . . .' She paused and took a sip of water. 'One of them chased me down it. The other one must have run down the stairs inside the building, because he was waiting for me when I got round to the front.'

'God, Angela. I hadn't realized.' Bronson reached over and took her hands, squeezing them gently. 'How did you get away?'

'I hit him with my laptop bag. It caught the side of his head, and that gave me enough time to get out on to the road. There was a black cab passing, and I ran across and jumped in. The driver saw what was happening and just drove off before the two men could grab me.'

'Thank God for London cabbies.'

She nodded enthusiastically. 'If he hadn't been there, they'd have caught me. There were people about, Chris, lots of pedestrians, but these guys just didn't care. I was terrified.'

'Well, you're safe out here – I hope,' he said.

Angela nodded and sat back in her seat. Explaining what had happened had been almost cathartic, and she felt herself regaining her normal composure.

'The good news is that my laptop seems to have survived the impact. And then I enjoyed a bit of retail therapy at Heathrow, hence the new suitcase and stuff.'

'I hadn't noticed,' Bronson admitted.

'I'm not surprised,' Angela said. 'You're only a man, after all.'

Bronson grinned at her. 'I'll ignore that. I'm really glad you're here, you know.'

'Now, before we start,' Angela said, her face suddenly serious, 'we need to establish the ground rules. You and me, I mean. You're out here because you're trying to find out what happened to the O'Connors, and I'm here because I was frightened about what had happened in London.'

'So what are you saying?'

'We've been getting along better these last few months, but I'm still not ready for the next step. I really don't want to get hurt all over again. So separate rooms – OK?'

Bronson nodded, although Angela could almost taste his disappointment.

'Whatever you want,' he muttered. 'I did book you a separate room at the hotel.'

Angela leant forward and reached for his hand. 'Thank you,' she said. 'I want it to be right for us both.'

Bronson nodded, but still looked concerned. 'One thing you need to understand, Angela. Morocco might not be any safer for us than London,' he said and explained what had happened at the Philips' hotel. 'I told you about that gang of thugs who chased me. I've moved to a different hotel, just in case they'd managed to find out where I was staying, but we'll have to keep a low profile.'

Angela smiled at him. 'I expected that,' she said. 'How's David Philips?'

'He's OK – he didn't even need stitches. He's got a nasty bruise on his forehead, and I guess he's nursing a weaponsgrade headache. Whoever attacked him used something like a cosh.'

'And you don't think it was just a typical hotel theft?'

'No. I checked their room afterwards, and it had obviously been thoroughly searched. The laptop was the only thing missing, and the thief ignored their passports, which were on the desk in the room, and didn't touch their money or the credit cards that David Philips had in his pocket. The theft was almost exactly the same, in fact, as the robbery at their home in Kent. In both cases, it looks as if the thieves were after their computers, nothing else.'

'And that means?'

'Well, neither computer had much intrinsic value, so the thieves must have been after the data on the hard disks, and that means the pictures of the tablet. Can you trust your guy at the British Museum? Because no matter what he thinks about that lump of fired clay, somebody – apparently with international connections – obviously thinks it's important enough to mount almost simultaneous burglaries in two countries, and knock David Philips out cold when he got in their way.'

Angela didn't look entirely convinced. 'I asked Tony Baverstock to take a look at the pictures, and he's one of our most senior ancient-language specialists. You're not seriously suggesting that he's involved, are you?'

'Who else knew about the pictures of the clay tablet? At the museum, I mean?'

'I see what you're getting at. Nobody.'

'So suspect number one has to be Baverstock. Which means he could even have been involved in your burglary as well. More to the point, it also means everything he told you about the tablet might be deliberate misdirection. What did he say, by the way?'

Angela shrugged. 'He thinks the tablet was most likely used in a teaching environment, something like a basic textbook, and he was adamant that it's not valuable.'

Bronson shook his head. 'But it must have some value, because I still think it's likely the O'Connors were killed to recover it.'

'But Margaret O'Connor took pictures of an argument in the souk. Couldn't the killers have wanted to silence her for that reason, and stole the camera to remove the hard evidence?'

'That might well be a part of it,' Bronson conceded. 'It would explain why the camera and memory stick weren't found in the wreckage. But unless Margaret O'Connor threw away the clay tablet before they left Rabat, somebody took that as well.'

'And you don't think she just chucked it away?'

'No. Kirsty told me her mother was going back to the souk the next morning to return the tablet to the man – the Moroccan – who'd dropped it, and if she couldn't find him she was going to take it back home with her as a souvenir of their holiday. She put all that in the email she sent to Kirsty the evening before she and Ralph left the hotel. But by then the Moroccan was lying dead outside the medina with a stab wound in his chest – Kirsty got a final message from her mother the following morning, telling her she'd actually seen the dead man. Talabani's confirmed he was one of the people Margaret O'Connor photographed.'

'Margaret didn't say what she was going to do with the tablet, though?'

'No. Her last message was very short, just a couple of lines, probably sent while her husband was paying the hotel bill or getting the car or something.' Bronson paused and leant forward. 'Now, the tablet. What did you manage to find out about it?'

'As I told you on the phone,' Angela replied, 'it's a lump of clay of almost no value. The writing is Aramaic, but Baverstock told me he could only translate one line. And I think he was probably being honest in that at least, because he knows I can read a little Aramaic. If he was trying to mislead me, all I'd have to do to check that would be to compare his translation with the original.'

'And have you?' Bronson asked.

'Yes. I looked at a couple of the lines on the photograph, and I came up with the same words.'

'OK,' Bronson said grudgingly, 'for the moment, let's assume he is being accurate. Tell me what he said.'

'On that single line of text, the words are clear but they don't make sense. I've got a translation of that line and another couple of words written out for you.'

'Is there anything special about the tablet? I mean, anything that would make it worth stealing, let alone killing someone because of it?'

'Nothing. Baverstock found a part of a word that might refer to the Essene community at Qumran, but even that's not conclusive.'

'Qumran? That's where they found the Dead Sea Scrolls, isn't it?'

'Yes, but that's probably irrelevant. As far as Baverstock could tell, the tablet didn't originate at Qumran, but simply mentions the place. What's interesting is that one of the few other words he translated was "cubit".'

'And a cubit was what?' Bronson asked.

'It was a unit of measurement equivalent to the length of a man's forearm, so it was pretty variable – there were at least a dozen different sizes, ranging from the Roman cubit of about seventeen inches up to the biggest, the Arabic Hashimi cubit of nearly twenty-six inches. But the fact that there's a mention of a cubit could mean that the tablet is written in a type of code, and it might be indicating the location of something that's been hidden. Maybe that's why it's important.'

'Let's face it,' Bronson said, 'if Baverstock was being accurate, the inscription has to be a code of some sort. Nothing else makes sense.'

'I agree. Here' – Angela opened her handbag and fished around inside it – 'this is the translation of the Aramaic.'

Bronson took the single sheet of A4 paper from her and quickly scanned the list of about half a dozen words.

'I see what you mean,' he said, looking at the text more carefully. 'Did Baverstock think this might be encrypted?'

'No, but his field of expertise is ancient languages, not ancient codes, and that's something I do know about. The good news is that we're dealing with an object that dates back around two millennia. And that's good because although there are very few known examples of codes and ciphers from that period of history, those that we do know about are very, very simple. The best known was probably the Caesar Cipher, which was allegedly used by Julius Caesar in the first century BC to communicate with his generals. It's a really basic monoalphabetic substitution cipher.'

Bronson sighed. He knew that Angela had done some research on cryptology as part of a project at the museum. 'Don't forget I'm just a simple copper. You're the one with the brains.'

Angela laughed. 'Now why don't I quite believe you?' She took a deep breath. 'To use a Caesar Cipher, you write out the message as a plaintext, apply whatever shift you've selected to the alphabet, and then transcribe the enciphered message.'

Bronson still looked blank, so Angela moved her empty plate to one side and took a piece of paper and ballpoint from her handbag.

'Let me give you an example. Say your message is "move forward",' she said, writing the words in capital letters on the paper, 'and the shift is left three. You write out the alphabet, then write it out again underneath, but this time you move each letter three places to the left, a socalled left rotation of three. So you'd find "A" directly above "D", "B" above "E" and so on. In this case, the enciphered message "move forward" would read "pryh iruzdug". The obvious problem with this method is that every time a particular letter appears in the plaintext, the same enciphered letter will be in the coded message. So in this example, which is only two words in length, two letters – the "R" and "U" – are repeated, and somebody trying to decrypt the message can use frequency analysis to crack it.'

She looked hopefully at Bronson, who shook his head. 'Sorry, you'll need to explain that as well.'

'Right,' Angela said. 'Frequency analysis is a simple method of cracking a basic code. The twelve most common letters in the English language, in order, are "E", "T", "A", "O", "I", "N", "S", "H", "R", "D", "L" and "U". I remember it as two words – "ETAOIN SHRDLU". And you probably already know the most famous example of a Caesar Cipher.'

'I do?' Bronson looked blank and shook his head. 'Help me out here.'

'2001,' Angela said, and sat back in her chair. '2001 – A Space Odyssey. The sci-fi film,' she added.

Bronson frowned, then his expression cleared. 'Got you,' he said. 'The film-makers didn't want to use the acronym "IBM" for the computer on the spaceship, so they came up with the name "HAL", which, if I've understood you correctly, is a Caesar Cipher with a right rotation of one.'

'Exactly. There's another slightly bizarre example,' Angela said. 'The French "oui" becomes the English "yes" if you apply a left rotation of ten.'

'Do you think anything like that is probable in this case?'

'No,' Angela replied, 'and for one very simple reason: we can read the Aramaic words on the tablet. One of the obvious problems with a Caesar Cipher is that every word of the enciphered text is invariably gibberish, which is the biggest clue that the message is encrypted. That definitely isn't the case here.'

'What about other kinds of ciphers?' Bronson asked.

'You've got the same problem with all of them. If the individual words are encrypted, they cease to be recognizable as words and end up as collections of letters. The Aramaic words on this tablet' – she tapped the paper in front of Bronson – 'aren't encrypted. But that doesn't mean there isn't some kind of message hidden in the text.'

'You need to explain that,' he said, 'but wait until we're back on the road.'

'Just wait in here a second,' Bronson said as they reached the door of the restaurant. 'I want to check there's nobody waiting for us out there. Then I'll bring the car over.'

Angela watched him walking around the handful of cars parked outside, glancing into each of them, then stepped through the door as Bronson pulled the hire car to a halt just outside.

'So if the words aren't encrypted, how can there be a message in the text?' he asked, as he pulled out on to the main road.

'Instead of an alphabetic substitution, you can use word substitution. You choose particular words to mean something completely different. The Islamic terrorist groups have been doing this for quite some time. Instead of saying something like "We will plant the bomb at three this afternoon" they say "We will deliver the fruit at three this afternoon".'

'So the sentence still makes sense, but the apparent meaning is entirely different to its real meaning,' Bronson said.

'Exactly. Shortly before the attack on the World Trade Center, the lead terrorist, Mohammed Atta, contacted his controller and passed him a message that made no sense to the American security forces at the time. He used a sentence that included a phrase something like "plate with one stick down, two sticks". With a bit of imagination, you can see that he meant the numbers "9" and "11". He was actually telling his al-Qaeda contact the exact date when the attacks on America were going to take place.'

'And on this tablet?'

Angela shook her head in the darkness of the car, the headlamps boring a tunnel of light down the almost empty road in front of them. 'I don't think there's anything like that incorporated in the text, simply because the sentences don't make sense.'

She paused as she looked through the side window at the clear night sky. Casablanca was now several miles behind them, and away from the light pollution of the city, the stars looked brighter and closer, and far more numerous, than she'd ever seen them. She glanced back at Bronson, glimpsing his strong profile in the faint light cast by the jade-green illumination of the dashboard instruments.

'But there's one possibility that we haven't even considered,' she said.