In 'Bad Business,' Robert Parker's latest Spencer novel, the witty Boston private detective is hired to investigate marital hanky-panky at an Enron-like company called Kinergy. Spencer hardly has time to find out the name of the person he is supposed to investigate before the man is found dead. Some of the Spencer mysteries score high on action and low on plot (e.g. 'Potshot'). 'Bad Business' is just the opposite. There are murders here, but they take place 'off camera,' so to speak. I knew this book was getting cerebral when Spencer asks someone if he is familiar with the character Pandarus in Chaucer's Troilus and Criseyde. Later, he discusses various kinds of accounting practices with a C.P.A