On the jacket of Robert Galbraith's The Cuckoo's Calling, a mystery published in April, the author is described as a former military cop who left the service in 2003 ''and has been working since then in the civilian security industry.'' Turns out that is a fiction as fanciful as the book itself. As everyone now knows, Galbraith is actually a pseudonym for Harry Potter creator J.K. Rowling. Careful readers of the cleverly plotted book, which had sold roughly 1,300 copies in the U.S. prior to the revelation, might have detected hints of Rowling's distinctive style such as a penchant for inventive character names. The hero is a London private detective named Cormoran Strike hired to investigate the supposed suicide of biracial supermodel Lula Landry. His sidekick is Robin Ellacott, an inquisitive twentysomething temp secretary who at first struggles to find Strike's office because it seems to be situated in Diagon Alley (''She found it almost accidentally, following a narrow alleyway called Denmark Place...'').
Like Lee Child's Jack Reacher, Strike is a burly ex–military cop with methodical investigative skills; he also has an artificial right leg (due to a land mine in Afghanistan), a posh former fiancée, and a backstory that doesn't feel fully lived-in. Rowling is better at developing Robin, a resourceful Yorkshire gal thrilled to be in London and helping a real live PI, and at capturing the colorful celebrity culture, from paparazzi chases to Lula's seedy actor-musician boyfriend. Despite the contemporary milieu and sprinkling of F-words, The Cuckoo's Calling is decidedly old-fashioned. Rowling serves up a sushi platter of red herring, sprinkling clues along the way, before Strike draws a confession out of the killer in a climax straight out of Agatha Christie another best-seller who occasionally wrote under a pseudonym. B+