TroubleBy: Jesse Kellerman Saving lives is Jonah Stem's job but he usually does it at the hospital, not at 3 a. m. on the dark streets of Manhattan. When he impulsively intervenes to save a beautiful woman from a man menacing her with a knife, killing the attacker in the process, he is transformed from an overworked medical student to a hero in the media spotlight. The woman, Eve Gones, is profoundly grateful, and wants to show it. Before long, they're