It all begins on a Monday, when four people board an elevator in a Manhattan office tower. Each presses a button for their floor, but the elevator proceeds, nonstop, to the top. Once there it pauses for a few seconds, but the doors don't open. Instead, the elevator begins to descend floor-by-floor. Then it plummets. Right to the bottom of the shaft. It appears to be a random accident. . . . But on Tuesday, it happens again, in a different Manhattan skyscraper. And then Wednesday brings yet another tragic high-rise catastrophe. In only three days, one of the most vertical cities in the world—and the nation's capital of media, finance and entertainment--is plunged into chaos.