Mud and pigs are crucial ingredients in the coming season of "Downton Abbey."

That tony drama won't start until Jan. 5 on PBS. But the DVD came in the mail on Friday, and I wanted to see how everyone was doing after last season's shocking conclusion.

What was going to be a short visit to the most-watched drama in PBS history turned into a Saturday marathon.

But, oh, what a lovely, engrossing marathon. Series creator Julian Fellowes knows how to hook a viewer.

The fourth season is every bit as good as previous seasons. The last two hours weren't sent out, but I have a hunch that the mud-and-pigs scene was a crucial sign to how it all plays out. (Shirley MacLaine and Paul Giamatti appear in the season finale.)

The Crawleys have moved into 1922 to wrestle with changing times and numbing grief.

The death of Matthew Crawley (Dan Stevens) has put the drama on a new path. The additions of Lord Gillingham (Tom Cullen) and Charles Blake (Julian Ovenden) make that path transfixing.  

The chief theme is that the women assert themselves in new ways from business to leadership to love. Lady Mary (Michelle Dockery), Matthew's widow, experiences the biggest transformations, becoming more human and likable.

What is most striking, however, is that the older character actors perform with such brilliance. The new season's greatest asset may be the splendid team of Maggie Smith as the Dowager Countess and Penelope Wilton as Isobel Crawley. The characters bicker grandly but their bond deepens.

Jim Carter as Mr. Carson and Phyllis Logan as Mrs. Hughes deliver some of their best work yet. Writer Fellowes just keeps serving them first-rate material.

"The business of life is the acquisition of memories. In the end, that's all there is," Carson says.

"Downton Abbey" has certainly supplied some of the best TV memories of recent years. The new season continues that tradition.

If you want a refresher course, PBS is offering "Return to Downton Abbey" at 9 p.m. Sunday (tonight). Susan Sarandon hosts the program, which offers a preview of season four.