(CNN) -- "Harry Potter" creator J.K. Rowling donned an invisibility cloak of her own for her new novel. In top-secret fashion, she published "The Cuckoo's Calling" under the name Robert Galbraith. Her publisher, Mulholland Books -- an imprint of Little, Brown and Company -- described the author as a former member of the Special Investigative Branch of the Royal Military Police. "He left the military in 2003 and has been working since then in the civilian security industry," the publisher's website said. "The idea for (protagonist) Cormoran Strike grew directly out of his own experiences and those of his military friends who returned to the civilian world. 'Robert Galbraith' is a pseudonym."
@highlight
J.K. Rowling secretly wrote "The Cuckoo's Calling"
@highlight
The publisher pretended the author was Robert Galbraith, a former soldier and police officer
@highlight
It's been "wonderful to publish without hype or expectation," Rowling says
@highlight
Sales on Amazon spiked 507,000% after the news broke
The Cuckoo's Calling
Robert Galbraith
Cormoran Strike
Robert Galbraith
The Cuckoo's Calling
Robert Galbraith
"And to those who have asked for a sequel, @placeholder fully intends to keep writing the series, although he will probably continue to turn down personal appearances."
J.K. Rowling
J.K. Rowling
Rowling
While the novel received praise before the secret was out, the disclosure that @placeholder was the author -- to little surprise -- skyrocketed the book's sales.