When Dennis Sheldon lifted his head from his desk on Monday morning, he had already been dead for some hours. While working on Sunday afternoon in the dim electric hum of the otherwise empty office he had begun to feel queasy, had felt the half-expected chest pain, had seen the traditional bright light and had fallen forward, denting his now senseless forehead on the corner of his Italian marble desk-set. The desk-set had been a gift from his father.