Viera Kolarova, 35, a Czech who has lived in N.Y. for ten years, works for Martin Heckel, a would-be entrepreneur with big ideas, few brains, and no money. Still, Viera likes the job (little work or responsibility). . . until she finds her boss' unpleasant wife Myra murdered in the Heckels' Brooklyn apartment--a crime which is then followed by the disappearances of Myra's brother-in-law Yaakov, a diamond-cutter, and Abraham Epstein, diamond-dealing friend of the Heckels. Soon Viera is putting all her energies into some amateur slething; eventually she turns up the murderer and lands in the hospital. But forget the whodunitry: it's barely passable. The point here is rather that Viera is a disarming heroine--lazy, sensual, with a tendency to get drunk when things are very good or very bad; and her entanglements (struggles with saxophonist lover Paulo, flashbacks to romance in Prague, a sharply comic interlude in a 47th St. jewelry store) all illuminate the world of an honest, gutsy displaced-person. Splendid character, negligible mystery--a zesty first novel by a promising writer.