“But the inscription reads ‘To Helen, this is the condition I like to see my books in (read) JK Rowling.’

“And ‘read’ is underlined with two lines. It’s a brilliant inscription and relates absolutely directly to the book.”

Thankfully, Justin explained he would be valuing the books entirely on the basis in the writing.

“So I think I’d say possibly £1,000 to £1,500 on this, really just for the inscription.”

“Oh wow,” the guest replied, as he picked up the second book and continued: “And this, being a first edition – £3,000 to £3,500.”

Looking speechless, the owner commented: “Amazing.”

Antiques Roadshow airs on Sundays at 8pm on BBC One.