It's Memorial Day weekend, 1966, and Don's children are spending the holiday with him and his new wife, Megan, at the Draper's new and stylish Manhattan apartment. Pete struggles at SCDP because of Roger continually attempting to undermine him through his accounts. Joan, on maternity leave after giving birth to her son, Kevin, has a helping house-guest in her mother. Megan throws a surprise birthday party for Don at their apartment with all of Sterling Cooper Draper Pryce in attendance, except for Joan.