J.K. Rowling

J.K. Rowling at Wimbledon (Julian Finney / Getty Images / June 25, 2013)

A British law firm admitted on Thursday that it was the source of the information that J.K. Rowling had secretly published a mystery novel, "The Cuckoo's Calling," under the pseudonym Robert Galbraith.

Rowling's response? She is "very angry."

She wasn't at first. Initially, she was somewhat wistful. "I hoped to keep this secret a little longer," she wrote on her website. "[B]eing Robert Galbraith has been such a liberating experience! It has been wonderful to publish without hype or expectation and pure pleasure to get feedback from publishers and readers under a different name."

That pleasure was diminished when she learned that the law firm Russells was responsible for the leak. A partner in the firm let the secret slip to his wife's best friend, the Associated Press reports. The best friend tweeted about the real author of the pseudonymously published book to the London Times; the public tip-off sparked the paper's investigation.

Rowling's response, according to the AP, was displeasure. "[O]nly a tiny number of people knew my pseudonym and it has not been pleasant to wonder for days how a woman whom I had never heard of prior to Sunday night could have found out something that many of my oldest friends did not know."

"To say that I am disappointed is an understatement," Rowling added. "I had assumed that I could expect total confidentiality from Russells, a reputable professional firm, and I feel very angry that my trust turned out to be misplaced."

Russells is a 39-year-old law firm catering to "clients from the world of music, theater, film, television," it writes on its website. "Drawing on our extensive experience we are able to provide our clients with the top-quality service they demand. We always maintain the highest standard of professionalism and understand the vagaries and idiosyncrasies of the industries and markets in which we operate."

Except, maybe, for how to protect the pseudonyms of very famous authors. In a statement, Russells said "we apologize unreservedly" for leaking the information about Rowling's secret identity.

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