On Easter Sunday, Agnes informs Ada, Marian, and Oscar of her nephew Dashiell Montgomery's imminent arrival in New York. In need of a change after an emotional visit to Philadelphia, Peggy asks Marian about returning to 61st Street. Meanwhile, Bertha sidesteps Mrs. Astor to support the Metropolitan Opera House, and Oscar begins courting Gladys once again.

After giving Oscar his final verdict, George sends Clay to meet Mr. Henderson, the union leader at his Pittsburgh steel plant. Meanwhile, Agnes chides Ada for being too chatty during a visit with Luke Forte, Mrs. Fane arranges a match for Marian in Newport, Larry gets a new commission, and Peggy is welcomed back to 61st Street by all but one.

After receiving discouraging news about the Met, Bertha deals with rumors that are swirling about Larry. Fearing her sister's disapproval, Ada asks Marian to cover for her as she continues to see Mr. Forte. Later, Bertha vies for position with the visiting Duke of Buckingham, and, in Tuskegee, Peggy navigates a tense dinner with Mr. Fortune and Booker T. Washington.

While Ada questions whether to move forward without her sister's support, Agnes faces the prospect of living alone. In Newport, Bertha puts the finishing touches on the event of the season as Mrs. Winterton plots her revenge. After experiencing the best of the Tuskegee Institute, Peggy and Mr. Fortune witness the dangers of the South firsthand.

As George heads to Pittsburgh to deal with the potential strike, Bertha learns that the Duke will return for the Metropolitan Opera's opening night. While the staff chip in to help Jack, Bannister tries to retrieve an incriminating letter from the Russell house. Ada and Luke return from their honeymoon and Marian receives an invitation from Dashiell.

Against the backdrop of the biggest event in New York City's history, Bertha reconsiders her loyalty to the Met. Meanwhile, an engagement celebration leaves Marian with doubts, Peggy strives to make a difference in Brooklyn, George strikes a deal with Mr. Henderson, Oscar makes an alarming discovery, and the van Rhijn household reels as Luke's health deteriorates.

While the staff question their future in the van Rhijn household, Jack receives welcome news about his patent. After scoring a victory for the local schools, Peggy considers her future at the NY Globe. Later, Marian confesses her true feelings to Dashiell – and Bertha and Mrs. Astor make their final moves in the opera war.