Dr. Sagan compares the exhilaration of 17th-century Dutch explorers who ventured in sailing ships halfway around our planet in their quest for wealth and knowledge to an inside view of the excitement around Voyager's expeditions to Jupiter and Saturn. The newly acquired treasures of our present golden age of exploration are the focus of this episode.

A voyage to see how star patterns change over millions of years is followed by a journey to the planets of other stars, and a look at the possibility of time travel. This takes us to Italy, where a young Albert Einstein first wondered what it would be like to ride on a beam of light.