It's actually the second part of episode 10; but seeing as how ya'll get confused with the whole 10a and 10b thing, we're just calling it episode 11.  According to C.S. Lewis, if you put second things first, you lose both second things and first things.  The guys dive a little further into the conversation about popular idols in American culture.  

If you want to here more of what Lewis had to say, just search "second things first" essay's because in spite of his best efforts to bring it back to that topic, he forgets.