So how does the Dutch version of a book have lines that don't appear in the original English edition?
Not any random lines - but a highly damaging reference linking a member of the Royal Family to a race row that has rumbled on for years.
That's the royal puzzle after the Dutch translation of Omid Scobie's Endgame appeared to reveal the name of a person alleged to have made comments about the skin colour of the baby that Prince Harry and Meghan were expecting.
It's been presented as a mistake, a very embarrassing one, and the book has been hastily taken off the shelves. But how could it have happened?
The Dutch language edition, Eindstrijd, has a very plain reference to a senior royal and there have been claims of another much vaguer reference to a second name.
The publisher's managing director, Anke Roelen, said on Tuesday night: "An error occurred in the Dutch translation and is currently being rectified."
As a result, the publishing house, Xander Uitgevers, is "temporarily withdrawing the book", with its release day descending into chaos.
It's now going to be re-released on Friday, in a "rectified" version.
Although the blame was initially placed on the translation process, a comparison of the English and Dutch text doesn't suggest it's about getting some of the phrases or vocabulary mixed up.
The line identifying the member of the Royal Family isn't in the English text, so it hasn't been mistranslated. It seems to have been added.
And an updated message from the publisher now talks of an "error", without mentioning translations, if that has any significance.
The next thought might be that this was part of a draft or a previous edit that had been taken out of other language versions, but had mistakenly not been updated in the Dutch version.
But the author Omid Scobie, speaking on Dutch television on Tuesday, made it clear that any version he had produced had never named names. So that would rule out this having been a draft or remnant of some previous editing that had not been removed.
"There's never been a version that I've produced that has names in it," the author told the RTL Boulevard show.
"The book's available in a number of languages and unfortunately I can't speak Dutch, so I haven't seen the copy for myself, so if there have been any translation errors I'm sure the publisher's got it under control," said Mr Scobie.
In pre-publicity, he had made a specific point of saying that for legal reasons, he wouldn't identify the names involved in the race row that emerged from Prince Harry and Meghan's interview with Oprah Winfrey.
Prince Harry and Meghan themselves have never given the name of the person or persons, who were alleged to have asked questions about the skin colour of their as yet unborn baby.
As Meghan herself has observed about the potential consequences of revealing the name: "I think that would be very damaging to them."
After this was first revealed in the Oprah Winfrey interview in 2021 it sparked a royal race row, and questions about the identity of those involved have become a lingering cloud.
This latest book makes the claim that there were two people involved in asking these questions rather than one.
Apart from an update on Wednesday announcing a new release date, the publisher has still to say what went wrong - but that won't stop those trying to work out what happened.
Could it have been some kind of publishing version of a hack or a hoax? Was it a sales stunt? A prank? Stray text put in for a joke and then not removed? Or someone changing text after the proofreading was finished?
What's surprising is that any other news lines in the book were heavily trailed, including excerpts in the US press and in interviews.
So it might seem odd to bury the biggest bombshell in the middle of the book, without any subsequent explanation of this revelation, and without any kind of highlighting of the claim.
After this short line revealing the name, the Dutch text goes back to the same as the English, while you might expect it to reference back or expand on such a major revelation, which would be the biggest moment in the book.
If a publisher had decided to take such a big decision to reveal this information, it would be its biggest selling point as well as its biggest risk.
Either way, if it was going to be deliberately revealed it's hard to see why it would be tucked away as a single line, mid-text, rather than milked in every way to boost sales.
Buckingham Palace hasn't been commenting on what has appeared in the Dutch edition of Endgame, in a book that already had been taking aim at the senior members of the Royal Family.
The English-language publishers, Harper Collins, have also not responded.
In the wake of the Oprah interview, with its toxic questions about racism and the royals, the late Queen's response had included: "Recollections may vary."
In this latest Dutch whodunnit, it seems translations may vary too.
