It's not often you get summoned to the home of such fiendish inventions as itchy lavatory paper (purpose: to irritate the enemy) for a briefing on A-levels, but that's exactly what happened this week.
Yes, the Government's curriculum quango has moved to its new home - a rather nice London building which owes much of its peculiar design to the previous tenants, MI6. (Shhh. Don't mention fugitive ex-spy David Shayler or Colonel Gadaffi) Thus, Monday morning found assorted hacks ushered into a curious room whose previous incarnation was apparently as a bombproof lecture hall.
"It's like something out of a Bond film," whispered one, perhaps overawed by the aura of hot and cold running spooks. "You expected the walls to part at one end, revealing a map of Eastern Europe."
There is, allegedly, also a rubber-lined room in the basement with a small drain - the threatened destination for the hapless bosses of the Oxford and Cambridge exam board if they fail to outwit their dastardly computer and get their results out on time.
Perhaps fittingly, there is a certain degree of confusion over the address. For a start, the building's secret past meant it was never given a name, a state of affairs which continues to this day. The second is that it used to be in Piccadilly, one of London's most famous thoroughfares. To be precise, 83 Piccadilly.
But, mysteriously, all official correspondence for the Qualifications and Curriculum Authority must now be addressed to 29 Bolton Street ... a side road off Piccadilly. Puzzled callers relying on the official address have been spotted wandering up and down Bolton Street, asking increasingly desperately of car park attendants and the like, where the QCA is to be found. Eventually they discover a side door (complete, of course, with letterbox) and a polite notice asking callers to use the main entrance... round the corner at 83 Piccadilly.
Persistent rumours that top brass at the quango felt a Piccadilly address was, ah, a little too ostentatious for such an 'umble outfit must surely be wide of the mark. And, anyway, the Diary is a tad nervous about that rubber-lined room. So we rang for this official explanation: "Only 25 per cent of the frontage is on Piccadilly and the rest is on Bolton Street." So now you know.