Last night's episode of Mad Men was dense, contentious and extremely focused, it was unexpected and captivating. Instead of filling time with subplots, the episode was all Don and Peggy. And maybe it was one of their best.

It started like so many others, with casual racism and an iconic moment in our cultural history to center the action. It teased an episode about the dynamic of the company, now that it has three new additions in Rizzo, Cosgrove and Danny Siegel, and the relationship between Roger and Don. But, instead, we got something much closer to home, and, forsaking the David Chase School of Screenwriting's focus on subplots, Matthew Weiner gave an episode that was totally focused on the heart of the show.

As if it weren't clear, the heart of the show is Don's relationship to Peggy and to himself. Setting the episode against both the Ali-Liston fight of May 25, 1965 and the development of a campaign gave Weiner the chance to use every tool at his disposal to elucidate these relationships. We got all the history and closeness of their relationship and we also got the exact opposite, the angry and resentful part that presents during work. In an argument evocative of any boxing match, they let it fly about credit and money.

But Don and Peggy have a legitimate bond and this episode showed it. They share their devotion to work at the cost of everything, as this episode made explicit, vis a vis Peggy's break up with Mark. But they also know each other the best, knowing various pieces of sensitive information about each other. But, of course, not all of it - Don doesn't know how the father of Peggy's child is and she only kind of has a sense of him. He lets loose with her, but doesn't spill any real details when he finally has to confront the death of Anna Draper.

One other interesting point of note in this episode is that it reinforced how much Don is on the wrong side of history while Peggy is on the right side of it. Last week, we saw that Peggy could adapt to someone else's idea of bohemianism and best them at it, previously we saw her hold her own at a party broken up by police. But Don is looking more and more out of touch each week. A few weeks ago, he chose Ponds over Clearasil, ignoring the incoming teen culture revolution that it still a large force in our society. This week, he not only took sides against Muhammad Ali, who would become one of the 20th century's most beloved figures, even going so far as to ignore his name change. And, he took issue with the team's suggestion of using Joe Namath as a spokesman, obviously, from our perspective, a bone-headed move considering the era of the celebrity spokesman that was about to come and how large a star Joe Namath would be in four short years. It's amazing that the show can contrast Don's genius, from the outset (Lucky Strike) through the latest episode, with the fact that he's fast becoming a non-functioning relic. And how fitting it was that the client was Samsonite, with the baggage metaphor working perfectly.