You might think that a plot to blow up the Pope would be news for a while. Popes don't get blown up all that often, and this one's enough of a celebrity that if he fell over drunk at the MTV awards with Kanye West it would be in the papers for a few days, so it's strange that a plot to blow him up was only of interest for one day.

On Saturday, the front-page headline in the Express was "Muslim plot to blow up Pope", and every paper had a similar headline. So it seemed there'd be a massive search and meticulous security, with even the Pope himself getting frisked and being told: "Sorry, your Holiness, you're only allowed to carry 100mls of holy water on to the pulpit, though you can get another bottle after you've been through security."

But nothing more has been heard of it. Yet at the time it was so serious that, according to The Sun, the plotters, who were six London street cleaners, "had access to where the Pope is going to be". Because through the trick of becoming street cleaners, the conniving terrorists would be able to gain entry into the secret area of London known as "the streets".

The Telegraph elaborated on this, informing us: "As street cleaners they would have been able to move relatively freely through the crowds." Unlike the crowds themselves, of course, who wouldn't have been allowed to move at all but would all have been nailed to the pavement. And you can move much more relatively freely through a crowd when you're pushing a huge portable dustbin with giant brushes, so they were clearly a terrifying menace.

Luckily it's unlikely that being a street cleaner would have been enough to get all that close to the Pope, unless they were hoping to shout: "Hang on, Pontiff, you can't start Communion yet, there's a crisp packet under your cassock, I'll come and brush it away for you – KABOOM!"

So what happened to the plot? The most likely answer is obviously that its sudden disappearance was due to a miracle. But sceptics might suggest another explanation.

The Express told us: "The suspected plot was smashed." Other papers agreed it had been "foiled". But after the anti-terrorist squad raided the cleaning depot and arrested the six men, it turned out the only evidence against them was that someone had overheard them talking about the Pope, and they were released without charge. So the plot was smashed and foiled through the tactic of never having existed in the first place.

Maybe this is how the police can increase the number of crimes they solve, by foiling and smashing more such cases. They can announce the Armed Response Unit foiled a plot to kidnap Alan Titchmarsh by finding out no one wanted to kidnap him, and PC Whittaker smashed a plot to put a zebra in a wheelie bin when he worked out it wouldn't fit, and they'll be past their targets in a week.

So there was no plot; nothing, just a mix-up between the activities "talking about" and "planning to blow up". By Sunday night, the front-page declaration of Saturday's press turned out to have been utter nonsense. You might expect, if you were naive, this would mean those papers having headlines such as "Oh my God, we told you a pile of bollocks – we're so embarrassed." But instead the Express mentioned the plot's non-existence in one sentence at the bottom of page 9. Other papers probably went further, and just had a crossword clue: "Piece of ground that didn't happen to Pope perhaps (4)."

Another part of the story suggests a reason for all the excitement. Five of the six arrested were said to be from Algeria which, as The Sun put it, "is a hot-bed of Islamic fundamentalism". That's half a continent written off to al-Qa'ida, and a few more people thinking: "You know what those Algerians are like, they blow up Popes."

So the work is done, and they're free to make up the next one, such as "Muslims force Dalai Lama to harpoon a kitten" or something. It would have served them right if the Pope had to cancel the whole ceremony, having tripped over a dog-end as the road sweepers were all otherwise engaged.