1194, Nottingham Castle, Nottingham

‘Jay-zus, Becks!’ whispered Liam. ‘You were completely convincing back there. Does John … is he in love with you or something?’

She shrugged. ‘He has developed an infatuation for me. I have attempted to analyse why this is so and have no valid conclusions to make. He has said he finds “my unladylike fortitude bewitching”. The important factor is that this is useful leverage, which can be applied if needed.’

She hushed as a castle servant passed them in the small dark hallway. She beckoned Liam to follow her until she found a low wooden door on their left and stepped inside. They were in a small pantry; it was empty, save for several shelves laden with clay pots of preserves.

Liam reached out and grabbed her arms. ‘It’s good to see you again, Becks! Me and Bob were becoming worried about you, so we were.’

‘I have been in no danger,’ she replied calmly, with a hint of a smile for him. But then it was gone. More pressing matters to attend to. ‘John does not have the will or the courage to stand up to Richard. But my history database shows this siege does take place. That John does make a stand against him. Nottingham holds out for a week.’

‘That needs to happen, then, right? To ensure history is back to where it was?’

She nodded.

‘What about the Grail?’ said Liam. ‘Richard isn’t meant to get his hands on it, is he?’

‘There is no information on that in my files. This would indicate –’

‘That the Grail vanished. Ended up getting lost.’

‘Affirmative.’ She cocked her head, considering a suggestion. ‘We could destroy it.’

Liam shook his head. ‘No – no, I think there’s much more than we thought in there. Not just this word Pandora … there’s some sort of prophecy about the future.’

‘Prophecy?’

Liam told her everything he could remember Locke telling him. He told her about the robot he came back with, about the Templars who’d sent him. He talked uninterrupted for what seemed like ages. Finally, describing Bob chasing Locke off into the woods and retrieving the box. She now knew everything he did.

‘Then there may be strategically important information we can retrieve by decoding this document,’ she said calmly, gazing at the wooden box in Liam’s hands.

‘Exactly … and the only way to do it is using this grille thing out there, in King Richard’s possession.’

She shook her head.

‘What?’

‘I believe there is another factor involved.’

Liam frowned. This was already confusing enough for him. ‘What are you talking about?’

She reached under the layers of her gown, fumbling awkwardly for a few moments before pulling out a scroll of parchment. It was flattened and creased. He didn’t dare ask where that had been wedged.

‘This is a document known as the Treyarch Confession,’ she said. ‘This is an account of the discovery of a scroll dating back to –’

‘Bible times?’ cut in Liam. He remembered Cabot’s description of it months ago.

‘Affirmative.’

‘Where did you get it?’

‘That is irrelevant information. I have scanned the text of this and analysed the content.’

‘And?’

‘I calculate a fifty-seven per cent probability that the Treyarch Confession is the correct key for decoding the Grail.’

‘What?’ He looked at the creased and tattered parchment in her hands. ‘That’s the key?’

‘Fifty-seven per cent probability that it is. Correct.’

‘So what’s King Richard got then?’

‘A piece of worn leather with holes cut into it.’

‘Why? What makes you think that this is the real thing?’

She carefully unrolled the parchment until finally it was spread almost two yards along the stone floor. She pointed to illustrations in the margins on both sides of the text. ‘These decorative illustrations are common for the time. Typically they mirror the theme or message of the text. Observe,’ she said, moving her finger down one margin. ‘These illustrations are just simple geometric patterns. They have no discernible symbolism or meaning.’

‘They’re there just to make it look nice?’

‘Correct.’

Liam noted the patterns were intermittent; a dense and intricate block of cross-hatching and swirls about two inches high and wide, located every ten or eleven inches down the margin on either side.

‘The patterns are identical,’ Becks said. Liam looked more closely. Yes, they were. Line for line, curl for curl – the same ornate pattern.

Becks’s finger moved down the scroll and finally stopped. ‘Except these four.’ She pointed them out, two on each side. Liam struggled to see the difference by the guttering candlelight. His eyes strained as he studied them, again comparing lines and curves.

‘Look very closely,’ said Becks, pointing to a faint pen-stroke amid the pattern. The slightest hint of a minute cruciform easily lost amid the confusion of elaborate ink swirls. She pointed to another of the four. Again, the hint of a cross in a different location within the pattern. And then the other two. ‘The cross appears only in these four blocks of pattern.’

He looked at her. ‘So?’

Her brows knotted momentarily, perhaps a flickering learned gesture of impatience. ‘Each cross could indicate a corner.’

He looked back down at the parchment. She was, of course, right. ‘Four corners …?’

‘Four corners of a box.’

He looked back down again.

She continued. ‘I calculate with reasonable probability that this is an instruction on how to build a cardan grille to decode the Grail. The corners of the template would line up with the four crosses.’ She pointed at the handwritten text that would be framed by all four markers. ‘And some of the letters of the text within the template area should be identifiable as “window candidates”.’

‘What do you mean?’

‘You would mark where the letter was on the template, and cut out a small square of the template around it, thus creating a window.’

‘Ahh! I see,’ Liam grinned. ‘And you cut out all these little windows, and then you lay out this template on the rolled-out Grail and …’

‘Correct.’ She nodded. ‘Making sure you line the template up with similar corner markers. And the letters you see through the windows that you have cut out, spell the hidden message.’

‘That’s – that’s genius, that is! You could be right!’ He got up off his haunches and started to look around for something they could use. ‘We could make our own grille right here! Right now!’

‘No,’ she replied. ‘We can’t.’

‘Why not?’

‘We do not know which letters are the window candidates.’

Liam’s excitement vanished with a sigh. He’d assumed she’d already identified which were the ones.

‘On several occasions this document switches from Old English to another language. As you can see, it does so within the area marked out by the crosses.’ She pointed out the change of language to him. ‘I do not have this language file in my database. We have to presume there would be clues within this text to identify which letters are the window candidates.’

Liam scratched at his chin. ‘Would Bob know this language?’

‘No. We had the same files downloaded before the mission.’

Liam looked at it; he recognized some of the letters from the alphabet, but there were others that were totally alien to him. ‘Well … this is no good.’ He slumped back down again on the cold stone floor.

‘Suggestion.’

‘What?’

She began to roll the Treyarch Confession up carefully. Finally, gathered up, it disappeared again under the folds of her long dress.

‘Oh, hang on,’ said Liam, realizing what she was thinking.

‘You can’t take it to Kirklees, Becks! We’re surrounded by Richard’s army. It could end up falling into Richard’s hands.’

Becks reached for the candle flickering on the floor between them. ‘Then the alternative is that we burn both documents. Before Nottingham falls to King Richard. What is your decision, Liam O’Connor?’