John Lescroart's enjoyable but uninspired mystery unfolds like a classic Law & Order. San Francisco cop Abe Glitsky investigates the double homicide of a well-connected businessman and his enigmatic fiancée, then legal eagle Dismas Hardy hits the courtroom when his childhood sweetheart is accused of the crime. Upping the stakes for Hardy and Glitsky is the return of a nemesis from The First Law who threatens to unearth a guilty secret from their past. While The Motive's final plot twist nearly stretches past credibility, Glitsky and Hardy's camaraderie and banter (''Dull gets a bad rap. Give me dull anytime'') feel as comfortable as slipping into an old gumshoe.