A widely admired science-fiction writer returns to a favorite theme--biotechnology run amok--but this time entering the mainstream to offer up a thriller. FBI investigator Robert Cavanaugh is thrust into a murder case that keeps widening into new killings and that points simultaneously to the Cosa Nostra and the most advanced research in gene therapy. But Cavanaugh, as his superiors know, is hardly adequate to the task. An incurable romantic, he keeps embarrassing his ex-wife at work by sending her witty but odd faxes--until she puts a restraining order on him. No less well portrayed is Cavanaugh's informant, Judy Kozinski, a plump, unpretty woman married to an egotistical, unquestionably brilliant biologist who's murdered after a job interview with a mysterious biotechnical firm by the name of Verico. Then there's out-of-luck Wendell Botts, who, like Cavanaugh, is hopelessly in love with a woman who no longer loves him and who's gone over to a cult called the Soldiers of the Divine Covenant, taking their two children with her. A decent but tortured man, Botts is at last driven to violence when he can find no one to take his claim seriously that ritual human sacrifices are going on beyond the cult's barbed wire. It turns out that the murdered biologist was near a breakthrough in gene therapy that Verico, in league with the Cosa Nostra, planned to make use of for purposes that could have been enormous, altering the entire world's political landscape. Kress's first thriller passes muster, though her mafioso types are always offstage and far too efficiently evil to be believed. The author's real strengths lie in her ability to create characters who have recognizable frailties and sorrows, and pages that are simply brimming over with ideas.