In the Season 4 finale, a surprising opportunity rears its head for both Don and Peggy, leaving them with life-altering decisions to make.

While trying to navigate a crisis, Don encounters an old friend.

An all-hands meeting is called at Sterling Cooper Draper Pryce, and the gossip starts to fly about an important client leaving the agency and that possibly more will follow. Meanwhile, a competing firm attempts to poach select SCDP employees; Peggy has a passionate romp with Abe and later tries her hand at wooing the Playtex people.

Betty is a bit unsettled when a surprise visitor stops at the Francis home.

A romantic gesture in the form of a thoughtful gift could lead to professional problems for Peggy.

Peggy and Joan are forced to deal with some insulting office behavior; Don and his date Bethany (Anna Camp) have an uncomfortable encounter with Betty and her husband at a fancy restaurant. Later, during a late-night business meeting, Don invites Faye (Cara Buono) to dine with him, and dinner turns into a bit more than either had expected.

A rapidly approaching deadline causes consternation and throws things into a tizzy at the agency.

Peggy and her new creative partner don't see eye-to-eye; Don pitches a client under an unusual set of circumstances.

Don and Pete disregard Roger's expectations in an effort to land an important new client.

When Pete receives an edict from Roger and Lane, he finds himself confronting personal dilemmas at work and on the home front. Meanwhile, Peggy befriends Joyce, a photo editor at Life magazine, who invites the copywriter to a party at a downtown loft, where Peggy gets hit on from a number of sides. And Faye's self-deprecating remarks at a focus-group meeting don't sit well with Don.

Don plans a jaunt to Acapulco, while back at the office, Lane and Joan get into a serious disagreement.

The agency's Christmas party is nearly spoiled by the late arrival of a surprise and not-so-welcome visitor.

In the Season 4 opener, Don's reluctance to talk about himself jettisons a prestigious trade-paper interview that the company was hoping would be a boon to business. Meanwhile, the "wholesome" manufacturer of two-piece swimsuits wants to hire the firm but doesn't want a sexy ad campaign; Pete and Peggy stage a stunt in an effort to secure more money from a meat-company client; and Roger plays Cupid for Don.