Series Three: Episode One
Spring 1920. Preparations are being made for the wedding of Mary and Matthew. Mary's mother, Martha Levinson, arrives at Downton for the celebrations. She quickly clashes with the Dowager Countess due to her modern outlook and rejection of traditional English values.
Lord Grantham has invested most of Cora's money in railway shares which have collapsed, which could bring bankruptcy to the estate. Matthew finds that he has come into a large inheritance from Lavinia's father, but he feels that he cannot accept the money on principle (as he still feels guilty about his treatment of Lavinia). Mary and Matthew fall out over this, with Mary feeling that Matthew should put the good of the family before his own principles, and for a time the wedding is in doubt.
Branson and Sybil arrive from Dublin for the wedding (their attendance had been in doubt due to their lack of funds and also Lord Grantham's unwillingness to have his former chauffeur at the society wedding); he has an embarrassing moment when a former suitor of Sybil's spikes his drink to make it appear that he is drunk at dinner. However, the ruse is discovered and Matthew shows his acceptance of Branson into the family by asking him to be his best man. Branson repays this trust by having a heart-to-heart talk with Matthew which makes him realise his feelings and keep the wedding on track. Branson continues to assert his independence and talk about the Irish question, to the embarrassment of others, but he is somewhat abashed to find that the mystery benefactor who sent him and Sybil the money to attend the wedding is in fact the Dowager Countess.
Edith continues to appear enthusiastic about Lord Strallen, despite the family's misgivings that he is too old for her.
Alfred, nephew of O'Brien, becomes a member of the Downton staff. He finds it difficult to live up to the high standards set by Carson and also has to cope with attacks from Thomas (it seems possible that Alfred will become a valet without paying his dues, and Thomas resents this). These attacks look as though they may cause trouble between former allies O'Brien and Thomas.
Anna continues her battle to find a way to free Bates from prison, where he is having trouble with a new cellmate. A document written by Vera has been discovered which may prove helpful to Bates.