Lane's shameful secret comes to the surface with dire consequences. Don recaptures his hunger for success, and Sally experiences a major milestone.

Set among the events surrounding Martin Luther King's assassination, Peggy tries to get a new apartment, Ginsberg is set up on a date, and Don has a revelation during his weekend with the kids.

Don takes an impromptu trip. Betty has lunch with a friend. Harry lobbies for a cause. The partners consider a questionable asset.

Don has a visitor from his past. Stan embarrasses a superior. Peggy helps Ginsberg with a problem. Harry finds that he has a new ally at the agency.