Matthew agrees to accept his inheritance, investing in Downton Abbey so that the lifestyle can continue. It turns out that his former finance Lavinia sent a letter to her father before she died releasing Matthew of any responsibility to her. Daisy the kitchen maid had posted the letter.
When Matthew offers all the money from the inheritance from Reggie to the Earl, the latter insists it represents an investment, not a gift. In addition to the family being able to remain put, the servants will still have their jobs.
The second pleasant surprise was that Mrs. Hughes did not have cancer. The growth is a cyst. Before this was found out, Cora told her that she would be taken care of by the family. Such good relationships between management and labor in those days, or at least in this fictional depiction of life among the elites in Britain in 1920.
The unfortunate surprise is that Anthony jilted Edith at the altar. Everyone was in the church, the wedding feast had been prepared back at Downton Abbey. Although Edith is not a likable character no viewer (or family member like Mary) would wish such a reversal on her. Of course she is distraught. The consensus of the family is that Edith must be given some cause to serve. Will she ever marry? The odds are against it.
Since Matthew and Mary have a major investment in Downton Abbey, one wonders if they will start asserting their power.