Towards Zero by Agatha Christie

"I like a good detective story," he said. "But, you know, they begin in the wrong place! They begin with the murder. But the murder is the end. The story begins long beforethat- years before sometimes- with all the causes and events that bring certain people to a certain place at a certain time on a certain day............."

He nodded his head gently:

"All converging towards a given spot.....And then, when the times comes- over the top! Zero hour. Yes, all of them converging towards zero......"

He repeated, :Towards zero......."