3 - 1Secret Weapon, Part 1: Lost & Found Feb. 26, 1975- 3 - 2Secret Weapon, Part 2: Not Quite a Sleeping Beauty Mar. 05, 1975
- 3 - 3Secret Weapon, Part 3: Whose Side Are You On, Professor? Mar. 12, 1975
- 3 - 4Secret Weapon, Part 4: A Present from Russia Mar. 19, 1975