Read the excerpt from "Object Lesson, Part 2."

Ellery glanced at the clock.

9:29.

Six minutes left in which not only to find the money but identify the thief!

How does the author add tension in this excerpt?

Aman lives on the twelfth floor of an apartment building. every morning he takes the elevator down to the lobby and leaves the building. in the evening, he gets into the elevator, and, if there is someone else in the elevator -- or if it was raining that day -- he goes back to his floor directly. otherwise, he goes to the tenth floor and walks up two flights of stairs to his apartment.