The show must go on. No exceptions, excuses or explanations. After all, when you're a card-carrying member of the royal family during a time of crisis, there is nothing else to do but simply get on with it.
'It', in this case, is putting your best royal foot forward in a damage limitation exercise after a disastrous high-profile interview by one of your in-laws.
Speaking to Newsnight journalist Emily Maitlis last weekend, Prince Andrew denied any wrongdoing by associating with convicted paedophile Jeffrey Epstein, who died in August. The prince was addressing allegations by US woman Virginia Roberts that she was trafficked by Epstein as a teenager, during which times she alleged she had sex with Andrew three times. However, his response to the claims was baffling, offensive and a PR disaster.
As such, the timing of Prince William stepping out with Catherine, Duchess of Cambridge at the Royal Variety Performance this week couldn't have been better. Because for all their wealth and influence, the royals are a precariously built house of cards, the success of which is predicated on their ability to keep up appearances.
The couple, who are currently riding high on public support, used their Royal Variety Performance appearance as an opportunity to showcase the true art of 'being royal', which is simply dressing well and looking happy while you're at it. William and Kate are by now an established tag-team truly coming into their own.
The success of their double act is down to the fact the couple have known each other since they were teenagers, allowing Kate the time to observe royal behaviours from the outside, before gradually assimilating as she entered the royal fray.
Time is proving to be Kate's most valuable currency in the monarchy; she has had the luxury of 10 years of studying its goings on, and of practising her place in it to perfection, before assuming her place at the top table, having built a popular public profile along the way.
On Monday night, Kate and William beamed, appearing happier than ever; it wouldn't take a body language expert to analyse how comfortable they are in each other's company, and in their roles as husband and wife and as royals. They huddled together conspiratorially in their royal box as they enjoyed performances from some of Britain's best known entertainers.
The Duchess of Cambridge arrived in all her sleek but bouncy-haired glory to the London Palladium, gracefully exiting her chauffeur-driven car with the finesse only years of duchess-ing can create. No surprise also that the 37-year-old debuted a new gown; a semi-sheer lace with nude underlay effect by her most trusted label, Alexander McQueen.
McQueen is always a sure bet for the duchess, and wearing a design by creative director Sarah Burton is a guaranteed win for positive coverage. Fashion followers are reminded immediately of Kate's first - and most notable - time wearing the designer: at her wedding in 2011.
Memories of the royal bride walking up the aisle in Westminster Abbey create a subconscious psychological effect around the Variety Performance outing. This is a trusted love story that has grown over the last eight years.
Kate's royal evolution is now complete and this is mirrored by - or perhaps even precipitated by - her fashion evolution over the past year. Her self-possession and quiet confidence is fully apparent. The Queen favours the change - having been reported recently to be impressed by Kate's "keep calm and carry on" attitude, referring to her as "unflappable", according to sources in Vanity Fair.
Her fashion choice for the Royal Variety Performance has copper-fastened Kate's new status as one of the top trusted ambassadors for the royal brand.
Observers need only look back to her first appearance at the event as a guest back in 2014; she was a new mother to Prince George and had just announced she was pregnant with her second child, Princess Charlotte. Her dress, and low chignon bun, was a conservative option, reflective of her preferred pregnancy style.
In 2017, while expecting third child Prince Louis, Kate adopted a bolder approach in the form of a powder blue sequinned Jenny Packham gown. Her hair, this time shoulder length, was new-mum functional, in comparison to her longer, more confident style now.
Last week marked the latest in a strong list of style victories for Kate in 2019, reflecting her confidence in her role and in herself. We saw an elevated version of the beloved McQueen dress, this time with some nude panelling underlay, giving the illusion of skin.
She shunned a necklace, her preferred accessory of choice after headwear, in favour of a pair of big and bold hoop earrings by British designer Erdem. It was the perfect balance of high-end home-grown designers, while offering enough intrigue to redirect interest towards the monarchy doing what it does best.
The Royal Variety Performance appearance also is a sign of the Queen's stamp of trust. It has been running at the London Palladium for the last 30 years and while Her Majesty is patron, it is one of the many high-profile gigs she has passed to the younger generation to make their own distinguishable mark as she ages.
Last year, Meghan and Harry attended as her ambassadors, but on Sunday, Harry marked his last public event for six weeks as he and his wife and their six-month-old son Archie take some time to spend with Meghan's mother Doria Ragland.
This leaves the Cambridges under even more pressure to promote the brand. In the past accused of being work-shy (especially in comparison to hard-working family members Princess Anne and Prince Charles), where there's crisis, there's opportunity - and these trying times present plenty of opportunity to capitalise on the strength of Brand Cambridge.
The couple have long been billed as the future of the monarchy, and they seem increasingly comfortable with the public aspects of their life as they prepare to become the Prince and Princess of Wales, and eventually king and queen consort.
Now, it is time for them to act. And, like many things in life, the actions that seem effortless to those on the outside are often the actions that require the most skill and expertise. In this regard, we would be foolish to underestimate the power of a dress.