A spokesperson for the series confirmed that Finneran, who was recently cast in the second season of BBC1 drama "The Syndicate," would not be back for the fourth season of "Downton," but it looks like O'Brien will be spared a sudden death due to scarlet fever or something similarly vintage and tragic, as it was noted that "the door could be left open for a return."
Carnival Films and PBS today also announced six new (and apparently much needed) cast members for the upcoming season. Most notably, "Weekend" lead Tom Cullen will play Lord Gillingham, an old family friend of the Crawleys who visits for a house party, and opera star Dame Kiri Te Kanawa will appear as a guest who, natch, sings in the house.
Nigel Harman will play Green, a valet; Dame Harriet Walter is Lady Shackleton, an old friend of the Dowager; Joanne David has a guest role as the Duchess of Yeovil and Julian Ovenden will play aristocrat Charles Blake.
Shirley MacLaine, who played Cora's mother Martha Levinson in several episodes last season, will return in the role for the fourth season finale.
Executive Producer Gareth Neame said in the announcement that "'Downton Abbey' has seen many great characters visit the house over the years and we couldn't be more thrilled to welcome the new faces that will be joining the regular cast of Downton Abbey in Season 4. We hope audiences will be as excited about them as we are."
The cast members aren't the only ones finding themselves drawn to new projects elsewhere -- creator Julian Fellowes landed a scripted historical drama called "The Gilded Age" at NBC in November.