‘Could anyone learn to do this?’

  ‘You’d need an in-depth level of experience, and you’d also, if you are savvy enough, use AI to help you. But,’ Shannon added, ‘once it has been set up, anyone computer-literate could learn to navigate it pretty quickly.’

  ‘So I could, or Glenn?’

  ‘Pretty well anyone, Roy.’

  ‘So what kind of people – by that I mean their background – would have the skills to do this?’ Grace asked Shannon.

  ‘A fairly wide number. There are plenty of trained computer programmers around the world who’d be able to. Some of them from military intelligence, too.’

  ‘How exactly does this auction take place, Shannon?’ Branson asked.

  ‘The way it’s been set up is using a forum called Dread – it’s probably the only forum on the dark web that is trusted, in that you can rely on stuff that’s on it. The Buckingham Palace thieves have posted a cryptic message on a Dread bulletin board, and clearly they’ve done this before, multiple times. Those who’ve been buyers before will recognize the message, and indicate if they want to register for the auction.’

  ‘What was the cryptic message?’ Branson asked.

  ‘Baking banana, white chocolate and raspberry cake.’

  ‘What?’ Grace frowned.

  Shannon smiled. ‘It’s totally innocuous and meaningless to anyone except those who actually know. It’s a signal to potential bidders. On the assumption this isn’t their first rodeo, they would already have user names and passwords issued, and the details of a Bitcoin account set up by the vendors, into which they would make part payment in the event of a winning bid, with the balance on delivery. Those interested would communicate with the vendors via an app called Telegram – which is end-to-end encrypted. As each bid comes in, it is invisible to all the others.

  ‘It was developed by two Russians,’ she added. ‘Designed to be completely secure.’

  ‘But not so secure that you couldn’t penetrate it?’ Grace quizzed.

  She answered blithely, ‘Nothing is too secure, if I’m given enough time.’

  ‘I take it you think other items stolen from the Royal Collection have been sold this way?’ Grace asked.

  ‘Either by auction or straight sale, yes. For sure. Whoever is behind this doesn’t think they’re leaving any footprints, but they are. They are smart – very smart indeed. But I’m more up to date and, more importantly, I’m smarter!’

  ‘And modest with it,’ Branson said with a grin.

  She gave him a strange look. ‘I’m with Muhammad Ali when he said, It’s hard to be modest when you’re as great as I am.’

  Branson was – for one of the few occasions in his life – left nonplussed and unsure how to respond. Grace came to his rescue.

  ‘OK, Shannon, so you are brilliant. That’s why you’re here and not still in prison. Are you able to identify the four bidders in the auction?’

  ‘Actually, there are now five bidders,’ she retorted.

  ‘Five? Where is the fifth one located?’

  ‘You’re looking at her.’

  80

  Tuesday 28 November 2023

  As soon as they walked back out of the flat and towards the car, Roy Grace’s mobile rang. It was Denton Scroope.

  ‘Hi, Roy. Good news, I agree with your wife about the code – it is definitely a variation of a Caesar Cipher. I’m pretty confident I’ve cracked the cipher – Sir Peregrine has used his initials PG for the key, which is P equals G, and so on for each subsequent letter. I’ve got the first of the remaining four deciphered: S O T H.’

  ‘S O T H?’ Grace repeated. ‘Have you worked out what that stands for, Denton?’

  ‘It could be something like Sanctuary Of The Heart or Shadows Of The Horizon. But given Cleo’s deciphering of A Rose Between Two Thorns, I favour either Song Of The Horseman? Or perhaps Son Of The Horseman?’ Scroope told him.

  ‘Neither means anything to me. Some allusion to the Four Horsemen of the Apocalypse, perhaps?’ Grace suggested, wracking his brains but not coming up with anything.

  ‘I’ll have a good mull on it. Is there anyone one who rides, I wonder.’

  ‘Or whose father rides?’ Grace suggested.

  ‘Indeed. The good news, Roy, is that having established the type of cipher, I should now be able to crack the remaining three.’

  ‘Great work, Denton. Really great work,’ Roy said. ‘I appreciate anything you can do.’

  Having reached the car, Roy then called Sir Tommy Magellan-Lacey’s mobile before getting in. The Master of the Royal Household answered almost immediately, his voice charming and friendly as ever but sounding a little anxious.

  ‘Roy! Everything all right? Any progress?’

  Grace was tempted to ask him if he knew any horse riders in the Royal Household, but decided it would lead to too many questions from the Master.

  ‘By the way, Roy, before I forget, I’ve arranged for you to see the box of Granny’s Personal Chips where it’s currently in storage, next time you’re in the Palace.’

  ‘Thank you.’

  ‘How did it go with Superintendent Mosse?’

  ‘Well, we’re not exactly besties, but I think we’ve established a constructive working relationship, Sir Tommy,’ he said, giving Branson a wink.

  ‘Good, that’s excellent news.’

  ‘There is one name that has come up as a possible person of interest in our enquiries,’ he said guardedly.

  ‘Yes?’ Tommy asked, eagerly.

  ‘Rose.’

  ‘First or last name?’

  ‘It could be either. You have Rose Cadoret who was in Kabul with you?’

  The Master nodded. ‘Completely trustworthy. There’s absolutely no way she would be involved in anything nefarious – well, it would be a complete surprise to me.’

  ‘I’m afraid that as a police officer, nothing is ever a surprise to me, Sir – er – Tommy.’

  ‘I’ll make some discreet enquiries about Rose Cadoret. I don’t recall anyone else with either the first or last name “Rose” in the Royal Household.’

  ‘Thank you, I’d appreciate that.’

  ‘Are your Sussex enquiries taking us anywhere closer? Any leads, suspects? I’m due to see both Their Majesties later this afternoon to give them a full update. Of course, the big question they are going to be asking is whether the deaths of Sir Peregrine Greaves and Geoffrey Bailey are connected or not. I’m actually on my way to see Superintendent Mosse now – do you have anything I can pass on to them?’

  ‘I’ve nothing new in terms of suspects, but we do have some intel that a very valuable miniature painting in the Royal Collection may have been stolen – or is about to be.’

  ‘What?’ the Master gasped, and Grace heard it. ‘This is credible information, Roy?’

  ‘Yes. I trust the source.’

  ‘Which – which painting?’

  ‘By Hans Holbein – Hans Holbein the Younger. It’s a miniature of Anne of Cleves. I can give you the RCIN number.’

  ‘No, don’t worry, I’m pretty sure I know where the picture is – it was one of many taken down for safety during the renovations and it’s in storage down in the vaults under the Palace. God, if you are right, this is unbelievable – outrageous.’

  ‘I am right.’

  ‘So on top of the murder of Sir Peregrine, which may or may not have been a failed assassination attempt on The Queen, then the brutal murder of a footman, we now have an art thief within the Royal Household? Where did you get this information from, Roy?’

  ‘I’d prefer to tell you when I see you, I don’t think it’s sensible to tell you over an open phone line.’

  ‘Yes, good thinking, very wise.’ He was silent for a moment, then he asked, ‘Roy, was your source able to say whether they think this is a one-off instance targeting this one picture – or are these buggers, whoever they are, going for others, too?’

  Keeping his cards tight to his chest, Grace replied, lying, ‘This is the only item I’m aware of.’

  ‘I’ll alert Lorraine McKnight, the Director of the Royal Collection, immediately. You say it may already have been stolen?’

  ‘My source wasn’t clear on this.’

  ‘I’ll get the guards to check all vehicles leaving the Palace, and all people carrying bags large enough to contain the painting – which isn’t very large at all – as soon as I’m off this call – but—’

  ‘Actually, Sir Tommy,’ Grace interrupted him. ‘I think we need to tread very carefully, and keep this information just entre nous. We don’t want to tip anyone off that we know about the plans for the picture. If it is still in the Palace then you have a very good chance of catching the thieves red-handed. Just make a discreet or seemingly innocuous enquiry – come up with some pretext why you want to see the picture, so you don’t raise any flags.’

  ‘Good point, Roy. But one thing puzzles me.’

  ‘Which is?’

  ‘Well, I don’t know how much the thieves have thought this through. The late Queen Elizabeth was particularly fond of this picture. It was she who made me aware of it, and of its significance. Hans Holbein the Younger’s miniature of Anne of Cleves is, frankly, one of the best known and most important paintings in the world – particularly due to its political significance. Every auction house and art dealer on the planet would know it immediately – they wouldn’t touch it with a barge pole, they’d know it was stolen from the Royal Collection. So I don’t quite understand what’s going on – unless these people think they are going to ransom it back to us.’

  In the background, Grace heard a faint sound he recognized. He glanced at his watch: 3 p.m. exactly. ‘I’ve had previous dealings with the criminal side of the art world,’ he said. ‘I don’t fully share your view about everyone not touching it. But it would be very helpful if we could start by establishing if the painting is still at the Palace or has already been stolen. If you could find that out urgently.’

  ‘And then set a trap if it’s still here?’ Sir Tommy said.

  ‘That’s exactly what I’m thinking.’

  ‘Absolutely,’ the Master replied. ‘I’m on it.’

  81

  Tuesday 28 November 2023

  Grace slipped his phone back in his pocket and filled Branson in on his conversation with Sir Tommy.

  ‘Boss, why did you hold back and not tell him what Shannon said, that this isn’t the first auction of items from the Royal Collection?’

  ‘Sir Tommy’s a nice guy, well-meaning and helpful. But at the moment we have to jump on whoever the thieves within the Royal Household are. Sir Tommy’s not a detective and if he starts digging around for us, we risk the people we’re after running for the hills.’

  The DI nodded.

  ‘We’ve got Shannon joining the bidding. Let’s see what she comes up with. She’s already said something extremely interesting that has got me thinking about Sir Peregrine in a different light.’

  Clipping in his seatbelt, Branson said, ‘Are you thinking what I’m thinking?’

  ‘Code?’

  He nodded, grimly. ‘Shannon said that the skills required could come from someone with a Military Intelligence background. Sir Peregrine’s military background was in Naval Intelligence, right?’

  ‘That’s what Lady Greaves told us.’

  A lightbulb had popped on somewhere deep inside Grace’s brain in their meeting with Shannon Kendall. Not a searingly bright one, but a glimmer, nonetheless. And steadily getting brighter. ‘Shit,’ he said, then fell silent, deep in thought.

  Branson looked at him, waiting for him to say something further, but the Detective Superintendent remained silent, his eyes closed.

  ‘Shall I head on down to HQ, boss?’ he asked.

  There was no response.

  Branson waited for some moments, then started the engine and reversed out of the parking space. As he did so, Grace suddenly raised a pointed finger. ‘Could this shed new light on Sir Peregrine’s death?’

  ‘What’s your line of thinking – although I think I’ve guessed it?’

  ‘We already know Sir Peregrine was into ciphers – using his old military code in his diary. Let’s hypothesize he was up to speed with modern computer code. Had he rumbled the conspiracy and was doing his own investigations on the dark web into who the conspirators were? And was that why he was murdered, to silence him? Or . . .?’ He looked questioningly at his colleague.

  ‘Or was he one of them – one of the conspirators? Is that what you’re saying?’ Branson looked dubious.

  ‘Up until now, we thought we had a clear motive for Sir Peregrine being the shooter’s intended target, from his coded entry in his diary. Now we potentially have a second one.’

  Branson drove in silence for some moments then he said, ‘Peregrine on the trail of the conspirators, or Peregrine not quite the loyal household servant Their Majesties believed?’

  ‘We’ve heard about his “proclivities”, thanks to the decoding of his diary. But what else can we glean from what he wrote?’ Grace glanced down at his phone, pulled up the decoded script and scanned through it, reading aloud various parts of significance to him.

  ‘A group of conspirators – let’s call them thieves . . . My source has discovered they are stealing high-value items belonging to the Royal Collection, which have been housed in the Palace. These items include ornaments, sculptures, paintings, small but rare pieces of furniture, and significant jewellery. An item on the target list is a priceless diamond of great historical significance from a collection known as “Granny’s Personal Chips”. My source told me they are planning to replace it with a fake that would be undetectable to the naked eye.’

  He went on.

  ‘If you are deciphering this it can mean only one thing, which is that The Hawk is dead . . . And, in particular, I want to expose the ringleader of this sordid little group. Someone who is high up in Royal Service . . .

  My source has given me this person’s name, but I’m frightened to reveal it . . .’

  ‘So who is this source? The Buckingham Palace Deep Throat?’ Branson said. ‘Or are we taking it all too much at face value?’

  ‘I’m thinking, is this all a very clever double-blind? The diary is in code, so why hasn’t he named either the source or this person high up in Royal Service? If he’s speculating he might be murdered for delving into the conspiracy, why would he have shied from naming this person high up in Royal Service, so they got their comeuppance? Could it possibly be that the “source” doesn’t exist and this person high up in Royal Service is actually himself?’

  Branson frowned. ‘But he must have been worried about being watched – and killed, to have written that diary entry in code. I don’t get what he’d have to gain from that.’

  ‘All part of clever obfuscation? Protecting his reputation, or his family’s inheritance in the event of his death, or perhaps both?’

  ‘What do we know about his finances?’

  ‘Financial Investigator Emily Denyer’s looking into them. She’s not found anything so far that raises a flag.’

  ‘Does he have a Bitcoin or other cybercurrency account?’

  ‘Aiden Gilbert’s Digital Forensics team have his laptop and phone. If he’s got a hidden account of any kind, they’ll find it.’

  As Branson drove on, Grace lapsed into brief silence again, deep in thought. Then he said, ‘This case is a proper onion router situation itself. Layers and layers to peel away.’

  ‘Exactly.’

  ‘And the first layer is the death of Geoffrey Bailey so soon after Peregrine’s. What we know so far is that the two of them were in some form of relationship that Peregrine felt was inappropriate, so he kept it hidden. We also know that Bailey desperately wanted a medal, which was in Sir Peregrine’s gift to recommend to The King. Killing Sir Peregrine wasn’t going to deliver him that medal, and from what we know of Bailey, he could never have planned the shooting. It was a proper military operation.’

  ‘Sir Jason, as well as Sir Tommy, and others in the Palace are all ex-military.’

  Grace smiled. ‘Yes, it seems half the Household staff are.’ He was silent again for some moments. ‘I’m trying to think of what motive there could be for killing both Sir Peregrine and Geoffrey Bailey. We know there’s the clandestine connection between them, so blackmail may be involved. That would be a neat fit. But killing both of them? Who has done that and what’s the motive?’

  ‘Lady Greaves would have something to gain. She learns about their secret meetings and kills them both.’

  ‘Elegant theory but I don’t see her as a modern-day Lady Macbeth,’ Grace said with a wry smile. ‘But she may be able to tell us something.’ He called Polly Sweeney, who said she was at this moment on her way to have a cup of tea with Lady Greaves, her second visit in two days. He asked her if she could urgently, in her role as Family Liaison Officer, ask Sir Peregrine’s widow if her husband had ever taken any refresher course in computer coding.

  Ending the call, he turned to his colleague. ‘Let’s look at possible motives.’

  ‘Jealousy, revenge, fear, anger and greed,’ Branson replied glibly. ‘Aren’t these what you always say are the main motives for murder?’

  ‘I don’t just always say them, mate. I know them by heart. Over twenty years working on homicides has taught me a lot about human nature. So which of the five you’ve just reeled off are you going to bet your stack of chips on right now?’

  ‘Greed,’ Branson replied almost immediately.

  ‘Greed is good,’ Grace replied.

  ‘Michael Douglas playing Gordon Gekko in the movie Wall Street. He said that. Famous line.’

  ‘Is there any movie you haven’t seen?’

  ‘Yeah, actually. I’ve got a few on my bucket list. I’ve never seen The Sound of Music. Nor Mary Poppins. Not really my thing, musicals.’

  Grace smiled. ‘I actually wasn’t quoting a movie when I said, greed is good. I actually think greed is a good hypothesis. Given the values of items in the Royal Collection, which we’ve had reinforced just now, greed has to be significant. Let’s look at the death of Sir Peregrine first. Two potential hypotheses. First hypothesis, Sir Peregrine stumbled across the conspirators and needed to be silenced. Second hypothesis, Sir Peregrine was one of the conspirators – their ringleader? Let’s go with the second for the moment, OK?’