India, May 22 -- Freida McFadden (But really, Dr Sara Cohen). Cohen treats brain disorders. But who'd trust a doctor who orchestrates a little fictional gaslighting on the side by writing thrillers? So, Cohen did the smart thing. She picked a nom de plume that was a medical in-joke: Freida, as in the Fellowship and Residency Electronic Interactive Database. It worked fine until one hospital colleague recognised her from her author photo. Wonder if that felt like solving a mystery too.

Robert Galbraith (But really, JK Rowling). The author who thinks gender is inflexible publishes some of her books under a man's name. Rowling says it's because, after the Harry Potter phenomenon, going with Robert made her feel anonymous for a change, and l...