Julianna ended the call. She sat at the kitchen table for a few minutes, then went out to the garage. A rope dangled from the trapdoor in the ceiling. The previous owner of the house had used a piece of string to attach a tennis ball to the rope. The string had been carefully measured: the tennis ball hung four feet off the floor, at the height of a car windshield. When the previous owner pulled in to the garage, the tennis ball told him or her exactly where to stop the car.
