Oliver Steele is a young British accountant who was convicted of fraud, went bankrupt, and now does odd jobs for Tisch, a billionaire living in the Caribbean. He is sent to recover $2 million that Tisch invested in a speculative venture and finds the killer of Ara Kalestian, the Armenian-American casino owner who promoted the deal. The quest takes him to Fresno, California, to meet the casino owner's widow, Las Vegas where he meets the promoter's colleagues, mistress, and son, and London and Monte Carlo, where he clashes with other suspects. As Oliver gets closer to the $400 million cache at the heart of the gambling game played by Tisch and his fellow investors, he runs afoul of an Al Qaeda plot to steal the money. Casino Excelsior is driven by the relationship between Oliver and Tisch'educated youngster versus seasoned Wall Street pro. For Oliver, relations with his crusty boss are complicated by Kathy, a friend of Tisch's young wife, whose intuition sometimes trumps his own more linear approach.