Dutton president Clare Ferraro did not, like many colleagues, return empty-handed from the Frankfurt fair. She carried with her a first-novel manuscript called Messiah, which HarperCollins UK is planning to do in mass market paper in the spring, and which she was sure could find an eager audience here too. Louise Burke, senior v-p and publisher of New American Library, agreed, and put in a six-figure preemptive bid for two books by the author so quickly that she doubts that many other publishers even got a look at the manuscript. The author, intriguing in himself, is Boris Starling, an unagented former reporter who has recently been working for a firm that specializes in kidnap negotiations and investigations -- good background for his tale of a London serial killer with a particularly brutal turn of mind who baffles the best minds at Scotland Yard. Burke described the book as "very dark but also hugely commercial -- one of the most frightening books I've ever read." As in London, the plan is to break Starling out to a mass audience in paperback, then go into hardcover for the second outing, which will involve one of the characters (not the killer) from the first one. NAL's Onyx imprint will bring Messiah out in paperback next September, and a Dutton hardcover of the second book, which Starling is writing now, should be out a year later.