This episode (The Prime Minister and the Prof) was my favorite of this season by far.
Here's the episode summary:
I won't say too much about the story in case you want to catch the episode. Gladwell takes his time to reveal the story with lots of great audio clips, an interview and a great background score.
I'll just say that it's a stark reminder that we should judge our leaders not just by their actions and words, but by the company they keep and the judgement those people show. For the simple reason, that a lot of authority will naturally be given to those people.
Churchill's blind trusting of his friend had devastating and far-reaching consequences. It's also a reminder that a lot of people are pretty terrible - that humanity isn't something that can be taken for granted and that they will often act in petty and self-serving ways that have devastating consequences.