Let the Great World Spin, by Colum McCann is constructed episodically to show time and life in motion. Picture eleven rivulets slowly pushing further from a source of melting snow. All rivulets are arranged around one central sphere that they will all reach as more snow melts and pushes their course forward toward the center. At the center is the event that thrusts them all together. It will be the central junction where all meet. In this metaphor explaining McCann's structure, the tightrope walker is the clock that all time moves in accord with. So the walker, besides being a tightrope walker having a great adventure, is two things: he is the background for measuring the movement of the rivulets and he is the measure of the progress of time.
McCann weaves from one character's story to another and back and forth again so you can see how they are progressing according to the one clock that unites them--the tightrope walker--and so you can see how they are all moving toward one central point, the point at which all their lives, lives of friends, family and strangers, all converge at a central destination against the same backdrop of the tightrope walker's adventure and at the central, pivotal event in the story. They progress slowly, as slowly as the tightrope walker, so you check the progress of one group of rivulets, then another, then another, then back to the first.
McCann has created a expansive and extended metaphor in Let the Great World Spin. Even while the related and unrelated people of New York watch the 110-story-high tightrope walker move slowly from a starting point to an ultimate destination, the reader watches these eleven people do the same thing as they move slowly from their starting points to their ultimate destination where they then collide with each other, metaphorically and literally. When they arrive, all unrelated lives, like Lara's, flow into other rivulets until all lives are united, just as the tightrope walker's rope and act unite the Twin Towers. The final union occurs when Jaslyn, who was raised by Gloria, who knew Corrigan and Tillie, goes to call on Claire. It is significant that they rest together at the end because the journey is finished; the last rivulet has joined the center: all are united. McCann brings a final comfort and ease to disrupted and at some times tragic lives.