The deaths of stars allow human lives to come into being. This episode explains how and looks at the complete life cycle of the stars that make up our galaxy. Two American scientists are shown researching the forces that bring gas and dust together with such intense pressure that nuclear fusion results and a star is born. Hans Bethe, the first scientist to explain in detail how stars are fueled, appears. Three Australian scientists look into the death of a star by studying the remains of the supernova explosion of 1987.

Efforts to discover other planetary systems and to learn more about the planets of our own solar system are examined. Images are shown that have been sent back to Earth by Voyager, the space probe exploring the outer edges of the solar system.