[Standard disclaimer: I have avoided reading any other recaps, writeups, or other commentary on this episode before writing this, so if I express something similar to thoughts you've read elsewhere, it's entirely a coincidence. If you have not watched the episode, assume there are spoilers ahead and act accordingly.]
Don't mess with Lane, huh? The outcome of the little bout in the conference room was never in doubt to me, but there was a lot of other good stuff leading up to it.
This was John Slattery's third time directing an episode, and I thought he did a very nice job, particularly with things like scene transitions, and I really liked the way light and shadow were used in the scene where Pete and Jenny are talking in front of the trophy case.
Kind of a reversal going on with Don and Pete, referenced through the episode. Pete's out in the suburbs with his house and family, while Don now prefers city life. Pete indulges himself at the brothel the way Don surely would have not very long ago while Don waits at the bar, and while he tries to tell Pete he isn't judging him for his behavior because he's done it himself, it still felt like he was.
It was good to see the old Roger, not the person buying favors but the person who's really good at his job, and who also generously offered advice to Lane (while Pete claimed he was "far too busy" to help Lane). I was rooting for Lane to land the Jaguar account, even while I suspected something would happen to derail it. It reminded me of when Joan was reading scripts for Harry in season 2's "A Night to Remember" and I wanted her to get promoted, while knowing she probably wouldn't.
And that led to Lane kissing Joan. I'd been wondering about a mutual attraction between the two of them for a while. Joan knew how he felt because she'd been in a similar situation, so she allowed him that one moment of inappropriate behavior, then got up and opened the door. Joan often communicates so much without saying a word.
And then there's Ken. I wouldn't have expected him to be writing science fiction stories, but I think that having that pursuit outside of work perhaps makes him the most balanced and stable of any of the men working at SCDP, and Roger isn't going to be able to force Ken to put that aside. And Ken and Peggy have a pact regarding employment elsewhere, which probably came about when the agency was struggling. Not the two most likely individuals to form such an alliance, but that sort of thing is common in advertising.
"Signal 30" is the name of the driver's-ed film, which in turn was derived from an old radio code used by law-enforcement agencies to indicate a death. At the time Pete was watching it, it was about seven years old, but it went on to be used in driver training classes for decades. If you are curious, you can watch the movie here.
One last thing: when Don said, "Let's make a baby" to Megan, she replied, "That's impossible." She was somewhat drunk, but still—perhaps she can't have children for some reason, and hasn't shared this with Don?