CCC6 - The Ambassadors of Death 6

Although this story carries the onscreen writing credit of David Whitaker, most of the actual work was done by Malcolm Hulke, who had just written Doctor Who and the Silurians. Hulke's contributions are evident in this story. One of his trademarks is that his villains are not necessarily evil, just misguided by our standards, or they're, at least, after their own agenda. Reegan,for example, isn't evil just to be evil. He just sees the aliens as a way to further his own ambitions of wealth and glory.

General Carrington's motives become clear towards the end of this episode. Like Reegan, Carrington's not evil either, but he legitimately believes that the aliens are a threat to Earth and that they should be destroyed. Soon, though, it's not so much the protection of Earth that Carrington is concerned about, but, rather, his desire to perform his "moral duty". This makes Carrington even more scary as a villain than any Dalek or Cyberman. Daleks and Cybermen don't feel any sense of duty in what they're doing. Carrington truly believes that what he's doing is what he should be doing.

There's also a fantastic exchange between Cornish and the Brigadier where Cornish chides the Brigadier for allowing Lennox to die whilst in UNIT's protective custody, then berates him further that UNIT has been very ineffective in their investigation of who is behind the kidnapping of the aliens. The Brigadier then goes on to explain the extraordinary lengths that he and his men have gone to in order to try and catch the criminals. Cornish relents in his criticism, but the Brigadier agrees with Cornish's first assessment. Despite the lack of success the Brigadier has had, these are still sunny days for UNIT - an all-powerful investigative team that, more often than not, get to the bottom of any situation they encounter with or without The Doctor's help.