A mysterious and magical world, featuring powerful potions, obedient elves, a flying car, public school rituals and imposing gothic architecture.

But that’s enough about Brexit, and the tendency of us Brexiteers to look on the bright side when discussing the restoration of self-government and departure from the European Union.

The Harry Potter author J.K. Rowling, creator of one of the most important British cultural achievements since the Beatles, spotted today that a piece by my friend the liberal leaver Dan Hannan MEP had been deleted or mysteriously disappeared, as if by magic, from the Reaction site. She was keen to draw attention to it, as in the piece Dan painted a sunny picture of life after Brexit as viewed from 2025.

Dan kindly wrote it for this site around the referendum, because I asked him to. Leavers wanted to portray an optimistic vision. They were hopeful in the event of a victory that all but the most angry Remainers would come round to the idea and work for a Brexit they could accept or even endorse. It has, to put it mildly, not quite worked out like that. The talks with the EU have been difficult. But the vision of prosperity and renewed confidence he lays out post-Brexit – and I don’t buy every detail – is perfectly achievable depending on the choices made.

But why was the piece deleted or disappeared? Did I quietly sneak in and press the delete button, to save Dan from any embarrassment? Or did he beg me to bury the piece? Or were there other strange forces at work? Perhaps a rogue London think tank going around covertly deleting anything that would embarrass Brexiteers? That would take a lot of deleting.

We launched a top-level investigation at Reaction. Russian interference is very fashionable. Could it have been that?

Alas, no. The explanation is more mundane. It is down to editorial incompetence rooted in my technological buffoonery. It was published in the earliest days of Reaction, and struggling to understand the difference I uploaded it on the test site rather than the real site. When the test site was shut down, or stopped being hosted, the post disappeared. We have fished it out, thanks to J.K. Rowling and someone who archived a version of it for some reason.

And now it is back on the site, as if by magic.