The G File

'Fifteen years earlier, a woman hired a detective to follow her husband, known as G to the police. Days later, she was dead. G was tried and cleared of her murder, but now, all these years later, the private detective disappears, leaving a note hinting he knows how G got away with murder. This is the final book in the series, but Nesser resists a showy finale, allowing his detective nearly to be outsmarted by an immensely clever criminal.