Editors who are also novelists are not unknown (Michael Korda at S&S, Star Lawrence at Norton and Joe Kanon, late of Houghton Mifflin, come to mind), but agents who take the plunge into fiction are a rarer breed. One such exotic is Neil Olson, president and senior partner at the Donadio & Olson agency, whose identity as a novelist was shrouded in the pseudonym Thomas Hall as his literary thriller The Icon made the rounds recently. Circulated by Sloan Harris at ICM, it's the story of a religious icon that reappears on the art market 60 years after it was supposed to have been destroyed by the Nazis in WWII. The preemptive buyer was executive editor Dan Conaway at HarperCollins, who bought world rights and promptly fingered the author's real identity. Olson called it "an amazing experience" being on the other end, so to speak, as a hot new book was circulating.