A muggle mystery is afoot in the U.K.Sometime over a span of a week and a half in mid-April, a burglar (or several) broke into a property in a Birmingham suburb, stealing jewelry and one item that's even more valuable — certainly to Harry Potter fans, at least: an 800-word, handwritten prequel to the series, scrawled on a postcard by J.K. Rowling herself."The only people who will buy this unique piece are true Harry Potter fans," West Midlands Police announced in a statement Friday. "We are appealing to anyone who sees, or is offered this item for sale, to contact police."The rarity sold for roughly $32,000 at a 2008 auction to benefit Dyslexia Action and English PEN, an advocacy group for free speech and human rights. The postcard is signed by Rowling and, according to CNN, graced with this postscript: "From the prequel I am not working on — but that was fun!"The New York Times sums up the story contained within the card's modest dimensions: