The impressive career of thrillermeister Robert Ludlum dates back to 1971's The Scarlatti Inheritance, though it was 1980's The Bourne Identity that put him on the map. And though he died in March of this year, it seems that his career--and blockbuster sales--might be around for a while. Cases in point: The Sigma Protocol grabs the #4 spot on PW's fiction list in its first week of sales, the same position held by the mass market edition of The Prometheus Deception, which marks its fifth week on that list. (The hardcover Prometheus enjoyed a nine-week tenure at the end of last year.) St. Martin's has mounted what associate publicity director Dori Weintraub calls "a huge TV campaign" for both books, including spots on CNN and Today. She notes that the author "left several manuscripts in various stages of completion, though Sigma Protocol was completely finished." PW's review of Sigma noted that Ludlum "displays once again his dazzling prose and ability to juggle an amazing number of plot lines." The publisher reports 500,000 copies of Sigma in print, and 1,240,000 of the Prometheus mass market.

With reporting by Dick Donahue.