48 Hours Investigates a real-life mystery about a young, well-liked and healthy research scientist named Eric Miller who suddenly gets extremely sick and dies. Doctors thought at first it was a virus that did him in, but that turns out to be wrong. It wasn't a virus. It was poison. Who wanted Eric dead… and why? Investigators are baffled as they search for a killer. And later in the hour, police investigate a picture-perfect marriage that – as in so many picture-perfect marriages - wasn't quite as it appeared. Lita Sullivan – beautiful, young - was ready to divorce her cheating husband when she was murdered by a delivery man bringing her flowers. Correspondent Susan Spencer tracks Lita's husband Jim Sullivan to Thailand to confront him about the case. Susan says that one of the intriguing aspects of the case is how Lita's parents are reacting. They're not bitter or vengeful, but because of their determination to get the killer, justice for their daughter may be in their grasp…nearly 16 years after her murder.