Does the Queen have Covid-19? A simple question to which, in the eyes of Buckingham Palace, there can be no simple answer.
On the one hand, there is an expectation the nation will be told if its head of state is temporarily unable to carry out her usual duties.
On the other, there is the medical privacy of a 95-year-old monarch who has already endured her recent ill health being pored over by a curious public.
While the Prince of Wales confirmed that he had tested positive for the virus for a second time on Thursday, moments before he was due to arrive in Winchester for a day of public engagements, the Queen's aides have been unable to offer no such clarity.
The Queen saw the Prince less than 48 hours before his positive test, meaning he would have been infectious when they spent time together over tea at Windsor Castle.
Palace sources have said only that the Queen has not experienced any symptoms of coronavirus ... yet. They pointedly refuse to confirm whether she has taken a test, let alone its result.
Citing medical privacy, they plan to update the public only when there is "something to say".
Taken at face value, most would assume that the monarch is awaiting the onset of symptoms, regularly swabbing for a lateral flow test or, given that she is the Queen, an expedited PCR.
At the very least, she will feel obliged to tell those who have seen her – Boris Johnson, who attended Windsor Castle for an in-person audience - and her closest aides and household staff whether they too were inadvertently put at risk.
With the Omicron variant proving mild for most, and the Queen fully vaccinated and boosted along with her age group, they may be little cause for alarm.
Yet the Palace's determination not to provide a "running commentary" on the not un-newsworthy matter has caused disquiet among royal watchers.
Only a matter of months ago, Nicholas Witchell, the BBC's veteran royal correspondent, was moved to complain that the public "weren't given the complete picture" after it emerged the Queen had spent a night in hospital for "preliminary tests" after falling unwell shortly after a public engagement.
Then, the news instead broke on the front of a tabloid newspaper.
In November 2020, it was revealed that the Duke of Cambridge had contracted Covid-19 in April of the same year, with the public never told for fear of it causing alarm.
The Duke had fallen ill not long after Prince Charles's first bout of Covid, but did not release the news via his press office because "there were important things going on and I didn't want to worry anyone".
On Friday, as the Duke flew home from Dubai, Kensington Palace similarly declined to reveal whether the Duchess of Cambridge had taken a Covid-19 test after spending the day with the Prince of Wales and Duchess of Cornwall six days before his diagnosis.
Neither the Queen nor the Duchesses have pre-announced public engagements in the diary that would require cancellation should they fall ill.
If Palace aides are so minded, the Queen – safe within a bubble of discreet friends and aides – could test positive for coronavirus and the public will never know.
However, while human decency dictates that they are not drawn into fuelling lurid "Fears for Queen's health" stories, it is not just a matter of public nosiness if the functioning of the state is in question.
Not only that, but the public care. Just as they would like to know whether their own mother or grandmother was suffering a cold, they will not be able to rest easy until the Queen is safely out of the Covid-19 danger zone.
"Rumour and misinformation always thrive in the absence of proper, accurate and trustworthy information," said Witchell last October.
It is as true now as it was then. The Queen and her aides may not want to worry anyone. But the public, holding its breath for Her Majesty as she begins her Platinum Jubilee year, are worrying nonetheless.