An exclusive prequel to Harry Potter auctioned off for charity has been stolen. Ever since J.K. Rowling's book series concluded with Harry Potter and the Deathly Hallows in 2007, fans have long hoped the author would again bring more adventures from the world of Hogwarts. And recently they've got just that, with Pottermore, stage-play Harry Potter and the Cursed Child and prequel movies Fantastic Beasts providing a bounty of wizard antics.

The idea of more stories has always been on Rowling's mind though. In 2008 she penned a prequel that followed the adventures of Harry's father James Potter and his godfather Sirius as they find themselves in trouble in the muggle world, which was auctioned off for charity. The untitled novella only stands at 800 words and was hand-written on both sides of an A5 postcard. Although short, the plot sees James and Sirius in a high-speed chase with muggle police officers and a dramatic finale where they escape on broomsticks. The postcard was sold at London auction house Sotheby's for a spectacular $32,000 and has risen in value since to be worth in excess of $77,000.

That story has been stolen from a home in Birmingham, England. A one-of-a-kind item, police have called the item "extremely valuable" and took to Twitter directly to appeal to fans of the sorcery series. Investigating officer Paul Jauncey asks anyone with any information to come forward as soon as possible.

Rowling had no plans to turn the idea into an official continuation of her book series and the acclaimed writer is urging fans not to buy the copy if it becomes available. The main worry at the moment is that the thieves will dispose of the ordinary-looking work without realizing its potential value.

The investigation is ongoing, but it's hoped the awareness will help resolve the matter.

Being the second-highest-grossing film series of all time and continuing with five Fantastic Beasts movies, there is certainly an air of magic still hanging over the wizarding world of Rowling's creation. And while talk is mostly about prequels, we are getting new adventures for the Boy Who Lived. The Cursed Child has been a smash hit on London's West End and is now set to come to Broadway, with rumors of a movie adaptation that brings back original stars Daniel Radcliffe, Rupert Grint and Emma Watson a la Star Wars: The Force Awakens rife.

Next: Harry Potter: 15 Craziest Things You Won’t Know If You Haven’t Read Pottermore

Source: West Midlands Police, J.K. Rowling