Introduces how lines of latitude and longitude are used on maps and globes, and includes an explanation of the equator, prime meridian, and more.

Although Molly in the United States is far away from the Inuit woman of Baffin Bay and the lonely sailor off the coast of Chile, they all eat breakfast at the same time because they are in the same time zone.

Recounts how John Harrision discovered the concept of longitude in the 18th century, thus making the waters safe for navigation.

Interweaves two stories: John Harrison's forty-year obsession with building his perfect timekeeper, known today as the chronometer; and naval officer Rupert Gould who, two hundred years later, stumbles across Harrison's forgotten chronometers and devotes himself to restoring Harrison's long-neglected mechanical masterpieces.