Sezon 4
Bölümler
1 Hitler's Secret Weapon 5 Oca 1977 2 The Hot Blooded Dinosaurs 12 Oca 1977 3 What Price Coal? 19 Oca 1977 4 The Sunspot Mystery 2 Şub 1977 5 The Plastic Prison 9 Şub 1977 6 Incident at Brown's Ferry 23 Şub 1977 7 Bye Bye Blackbird 2 Mar 1977 8 The Pill for the People 9 Mar 1977 9 The Gene Engineers 16 Mar 1977 10 The Human Animal 23 Mar 1977 11 The Wolf Equation 30 Mar 1977 12 The Dawn of the Solar Age 20 Nis 1977 13 The Business of Extinction 20 Nis 1977 14 The Red Planet 27 Nis 1977 15 Tongues of Men (1) 11 May 1977 16 Tongues of Men (2) 18 May 1977 17 Linus Pauling: Crusading Scientist 1 Haz 1977 18 Across the Silent Barrier 22 Haz 1977 19 The New Healers 29 Haz 1977