The entire third series of the ITV costume drama following the lives and loves of those above and below stairs in an English stately home. With World War One finally over, the 1920s heralds the promise of a new age for those at Downton Abbey. But while the family prepare for the wedding of Lady Mary (Michelle Dockery) and Matthew (Dan Stevens), Lord Grantham (Hugh Bonneville) learns that the future of Downton is in grave jeopardy after the collapse of investments made with his wife (Elizabeth McGovern)'s fortune. With the family beginning to gather for the wedding celebrations, a grand entrance by Cora's thoroughly modern mother, Martha Levinson (Shirley MacLaine), threatens to ruffle a few of the Dowager (Maggie Smith)'s feathers.