London ? Thousands of copies of the new Harry Potter book were stolen from outside a warehouse just days before the latest installment in the popular series was to go on sale around the world, police said Tuesday.

The twists and turns in the plot of “Harry Potter and the Order of the Phoenix” — the fifth book in J.K. Rowling’s series about a boy wizard — have been guarded with great secrecy by publisher Bloomsbury.

After the theft, police quickly threatened to prosecute anyone caught handling the book before its official release Saturday, and Bloomsbury pleaded for Harry’s secrets to remain just that.

“We hope that nobody will spoil the excitement for all Harry Potter fans who are looking forward to reading the book,” the publisher said in a statement — which included a reminder that a legal injunction bars publishing any contents or summary of the book before it goes on sale and requires the return of any missing books to the publisher.

Sunday night, the thieves made off with a tractor trailer containing 7,680 copies of “Order of the Phoenix” that was outside the Deacon Trading Estate in Newtown-le-Willows, northern England.