It's the big one, I thought. I will have to curtail the family holiday and do the honourable thing – phone the office.
I had been here before, when Princess Diana died, and sacrificed the first day of our summer break to return to the newsroom. It's what journalists do when a big story breaks. It is part of the professional obligation and is also, I suspect, influenced by vanity.
So when I turned on the BBC's Saturday night bulletin and saw royal reporter Nicholas Witchell appearing grim-faced outside Buckingham Palace I was mentally packing my suitcase.
Witchell was presenting the lead story, so it couldn't be trivial. Dressed in dark clothing, he looked close to tears and was speaking with such measured intonation that it had to be very grave news.
"The Prince of Wales has been kept informed of developments ... Official confirmation came late this morning ... Senior courtiers have been meeting ... An extremely difficult time for all concerned ..."
It could mean only one thing: the Queen was dead.
Then came the shocking realisation. The Queen wasn't dead. The news the BBC – and the rest of the media – chose to promote to the status of the biggest story in the world was this: that one of Mrs Windsor's grandsons had dumped his girlfriend. That's it.
It is a familiar story: boy meets girl at university, they fall in love, romp about when they should be attending lecturers, swap fluffy toys and cheeky underwear, endure the torment of meeting each other's parents, graduate, find their feet in the workplace, drift apart, fall out and split.
The stud muffin or sex goddess you fell for over a pint of Snakebite aged 18 is rarely the same person when they hit 24 or 25 – the respective ages of William Windsor and his "ex" (as she will forever be known) Kate Middleton.
The media has justified its fascination with the Wills-Kate romance on the basis that one day he might be king – and she, therefore, might become queen. This gave magazines and newspapers with big enough budgets carte-blanche to publish snaps of Kate in a bikini, Kate flashing "acres of fishnet-clad thigh" and Kate in skinny jeans. (Remarkably, Miss Middleton is one of the few women I have ever seen who can get away with pikey chic.)
All of these pictures show that William, despite his connections and pots of cash, got the far better part of the deal.
And here, I can reveal something of a royal exclusive: nothing less than the real reason why Wills and Kate split.
Many commentators have focused on the fact the prince felt too young to commit himself to Kate and preferred the hijinx of life as an Army officer to staying in to watch Poirot and snogging his girlfriend on the sofa. Wrong.
I can reveal the final straw was the Cheltenham Gold Cup last month. Kate agreed to wear tweeds as a sop to William's race-going fogeys but was stunned by the way her boyfriend, previously quite "street" in his dress sense, whole-heartedly embraced the nauseating colour-clashing corduroy and crusty sports jacket combo beloved of toffs.
A source confides: "Kate thought Wills liked baseball caps and gangsta rap. She almost puked when she saw what he was wearing. She felt betrayed."
Most sons start turning into their fathers in their 40s. It appears William's transformation was already underway and there was no turning back.
"Everyone feels terribly sorry for Kate but I'd call it a lucky escape," adds the source.
Here, here.