For the cast of “Mad Men,” the goodbyes took place last July when the critically acclaimed show filmed its final episode.

So the party last Sunday night, which celebrated the show’s final season, began another ending: the public goodbye to the AMC series that turned Jon Hamm, Elisabeth Moss and Christina Hendricks into stars; made skinny suits and retro cocktails cool again; and brought back “Zou Bisou Bisou” from cultural oblivion.

The party, held at the Museum of Modern Art, began with a screening of the first of the final run of episodes, and without giving much away, it’s clear that the adman Don Draper has not settled peacefully into middle age, or that his fellow colleagues Peggy and Joan have suddenly achieved equality in the sexist boys’ club of midcentury office culture.

“Dark, a real wrist-slasher,” is how Andy Cohen of Bravo, who wore a teal blue suit, described the episode. Judging by the epic mustache on John Slattery’s Roger Sterling character, the show’s awaited reckoning with 1970s style has also commenced.