Carl Sagan, who died in December 1996, is one of the few scientists whose name has become a household word all around the globe. The first man to recognise and name the "greenhouse effect", Sagan was a force behind the search for extraterrestrial intelligence. This is a behind-the-scenes look at Sagan's life and career in the field of space exploration and the evolution of life. Based on interviews with Sagan's family and colleagues, including his widow, his first wife, and his son, it reveals a roller-coaster of successes and failures, characterising a complicated personality whose life was one of continuous struggle.