The serial nature of TV can act on a show like wind resistance. Mad Men, like The Sopranos, had a great debut season partly because it could stand alone. The second season, on the other hand, spent so much time rebooting, its open-ended climax—Don's return to Westchester, Betty's pregnancy—felt like further set-up. But the third season sidesteps this issue with a spectacular season finale that revitalizes the show's plot engine. Don's identity, always Mad Men's core, is simultaneously stripped and souped up. He fights to keep his workplace family, but surrenders his home life without a fight. In the final scene, his colleagues literally move into his (hotel) room! Every strand of plot comes into play this final episode, possibly the show's strongest so far.
But even before the finale, season three displays tight writing and a growing integration (pun intended) between the characters' personal lives and the period's social change. The creators realize how superb Christina Hendricks is, adding substantially to her character's arc. Joan's dubious marriage and love of work acts as a foil for Don's while deepening the male/female dichotomy that's another central theme. A fine character is added to the cast (earnest, concise Lane Pryce) and another gets elaborated well (daughter Sally). Okay, #3 isn't perfect: as with season 2, Don's mistress is a wan character who won't be missed.
The bigger misstep is the forfeiture of Pete & Peggy's stature as secondary protagonists to give Betty a larger role. January Jones embarasses herself: there's no gap between the actor's emptiness and the role's. In a few scenes, she's outacted by 10-year-old Kiernen Shipka as Sally! It's especially frustrating since the universe of Mad Men bends around Betty like gravity. Hopefully, the upcoming season will readjust to its new status quo by giving Betty less screentime. The finale cut away much of the larger cast; ideally it'll pursue the intimacy that a newer, leaner firm affords the show!