Buckingham Palace boasts many intriguing features, including vast wine cellars (39,000 bottles and counting), a secret private indoor swimming pool and even its own post office, but one of the most hair-raising additions might be the $1 million-a-piece panic rooms that exist in all of the Queen's residences and which can withstand a mortar round.
If there was ever a week when Her Majesty might fancy shutting herself inside one of these security lockboxes with nothing but the complete works of Dick Francis, her new corgi puppy and an entire tin of Quality Street, then this is it, with the next week shaping up to be one of the most high-stakes periods in recent royal history.
The reason? Prince Harry of course, or to be fair, the return of the royal heretic for the unveiling of the much-anticipated statue of Diana, Princess of Wales alongside his brother Prince William.
The 36-year-old is already back in Britain having flown in from Los Angeles on Friday, UK time, and currently, he's holed up in Frogmore Cottage for five days of Covid-related quarantine. (Here's hoping the controversially renovated five-bedroom "cottage" has Sky Sports and the collected writings of Brene Brown so he can stave off boredom.)
On Thursday, William and Harry will stand side-by-side in Kensington Palace's Sunken Garden, an exquisite Edwardian addition that was one of their mother's favourite places, where they will debut the Ian Rank-Broadley statue of Diana they commissioned in 2017. (Thursday would have been the late Princess's 60th birthday.)
Make no mistake: This will be the most highwire meeting of the two men so far – the royal equivalent of the Yalta Conference, sans big moustaches.
For anyone out there harbouring any naive notions this princely reunion might amount to some bridge-building, or anyone who is tempted to start throwing around the word "healing," then I have some very bad news for you.
Going into this week, all signs are pointing to tensions between the princes remaining as bowstring tense as they have been for years now, with neither side showing any sign of relenting.
"Neither are offering an olive branch," a close friend of both brothers told the Times' royal editor Roya Nikkhah. "I fear it will be the same as at Prince Philip's funeral, a nod of recognition, and that's about it."
Those in royal circles, per the Times, are already "anxious" about this week's proceedings.
"On the day, it will be difficult to separate the statue from the occasion, which is now loaded with all sorts of unwelcome baggage," a royal source told Nikkhah.
"Of course they will put on a brave face for the event, like they did at the Duke of Edinburgh's funeral," the Telegraph's Camilla Tominey quotes one well-placed source as saying. "They both know it is not about them but remembering the late Princess.
"But the idea that this can all be forgiven and forgotten … it's going to take a lot longer than a couple of days."
Since late 2018, reports have only intensified and multiplied exponentially about the dismal state of the relationship between the Sussexes and the Cambridges. Harry and Meghan's decision to sit down with Oprah Winfrey in March this year for two hours of prime time grievance-airing has only seemed to pour fuel on the underlying anger and hurt. (No one wants their dirty family laundry aired in front of a global audience of 50 million people, do they now?)
"William is still angry about it," a close friend of both brothers told the Times. "It's despair, as well as anger."
"Before Oprah there was some sympathy for [Harry], but not after that," a source told the Telegraph. "He knew the damage he was doing. That he looked deeply uncomfortable tells you everything you need to know."
What should have been a powerful and touching gesture from the Wales brothers, the project, conceived to honour their mother when the bond between the two men was still largely intact, has now become a powder keg moment in the long and winding clash between the Sussexes and the wider royal family.
If all the players involved can somehow skate through this week without some sort of PR conflagration erupting, it will be nothing short of a miracle. (If ever there was a time for the Queen to use her godly connections as the head of the Church of England, this would be it.)
At risk here is more than just whether the palace can tamp down the roiling feud story that has dominated coverage for years now. Instead, at stake is the much bigger project of future-proofing the monarchy that is currently going on.
What separates the princes at this precarious stage is what they stand to lose if this state of royal affairs continues to drag on.
In the case of Harry, there is an argument that this narrative – the rebel prince standing up to the hoary, white palace; a man driven by love to protect his family in the face of a racist, antiquated imperialist hangover – is a boon for him back in the States. That is, defining himself in opposition to the royal family and everything that Americans think that stands for, only equates to some top-notch branding. More kombucha, anyone?
For William, things could not be more dramatically different. The last 18 months has seen both him and wife Kate, the Duchess of Cambridge dramatically ramp up their royal work, with him launching the $91.5 million Earth Shot Prize and the debut of the Kate-driven Royal Foundation Centre for Early Childhood, which was announced recently at the prestigious London School of Economics. This is all legacy-defining stuff and represents a dramatic and impressive departure from the prevailing royal status quo. William and Kate don't just want to politely do their bit for Gan Gan and country. They want to create real, generational change that will have a tangible and significant impact on the UK.
Unfortunately at the moment, all of this is perpetually overshadowed by the tantalising melodrama of the ongoing Sussex vs Windsor civil war.
That's why, on a purely pragmatic level, if William and Kate truly want to get the media's attention, and public interest, back on their paradigm-shaking do-goodery, then they need to find a way to draw a line under this whole sordid Sussex mess.
The longer this drags on, the more precious time the Cambridges are losing to cement a new, invigorating vision of the monarchy as the palace readies itself for the eventual passing of the Queen and the potential foment of Republican sentiment, especially in the Commonwealth.
They have a narrow window to prove, especially to younger Brits, that the monarchy is a genuinely positive and valuable institution in the 21st century and not a $169 million waste that carries with it deeply uncomfortable connotations of colonialism and white privilege.
As biographer (and The Crown's historical consultant) Robert Lacey wrote in the Daily Mail, "top figures in Buckingham Palace are working flat out to bring an end to the present emergency – and make no mistake, they view it as little less than that."
But no matter how furiously royal courtiers and aides might be beavering away to sort out this current situation, there is no denying the very clear and present danger this week poses.
So, Your Majesty, now would be a most opportune moment to gather that family-sized block of Fry's Turkish Delight you've been saving and your Line of Duty boxset and settle in. Those panic rooms might be mortar-proof but are they Sussex-proof? Now might be the time to find out.