1. Don is briefly replaced by Ron Draper, a previously-unmentioned brother from Sheboygan who doesn't get SCDP's "big city ways".
  2. Peggy sublets her apartment to a young marathon trainee...who turns out to be the one and only Bruce Jenner!
  3. Ken Cosgrove mounts an unsuccessful campaign for Mayor but then it turns out the votes were miscounted and he ends up as Mayor for a while.
  4. Don's pitch meeting with Lucky Strike goes awry when the track skips, and he is revealed to have been lipsyncing.
  5. Peggy buys Kodak and sells it to the Russians.
  6. Joan falls in love with a man named Chachie.
  7. It's revealed in the finale that all of Don's brilliant ideas have always been whispered to him by a man who lives in the ceiling, Eldon Carmichael.
  8. Eldon Carmichael is accidentally struck and killed by Mayor Cosgrove's motorcade as the credits roll.
  9. Then, the credits stop rolling suddenly. You think your television is frozen, but it's not. You, the viewer, have become the Mad Man.
    Bravo, Matt Weiner. Bravo.