Downton Abbey
"Downton Abbey" cast and crew members pose backstage at the 63rd Primetime Emmy Awards show in Los Angeles in September 2011. REUTERS/Lucy Nicholson

Something about “Downton Abbey” just reels viewers in.

Consistently mentioned in the same breath as other commercially and critically beloved television productions, the series -- shown by ITV in the U.K. and PBS in the U.S. -- doesn't have the suspenseful pacing of AMC's “Breaking Bad” or the moral ambiguity of the same network's “Mad Men.” However, the show has attracted legions of fans who will certainly be watching the American third-season finale this Sunday night.

It’s been a long third season -- or “series,” if you’re discussing the subject with British fans -- for the Crawley family. It began with Cora’s American mother, played with delicious snobbery by Shirley MacLaine, visiting the estate to attend Lady Mary’s wedding to Matthew, the heir to Lord Grantham’s fortune.

It was then revealed that the Crawelys were in dire straits, at risk of losing everything because of a string of investments that went from bad to worse after the Great War. Matthew, with no help from Cora’s mother, eventually offered a financial resolution that would save Downton and provide a stable future for the family.

Then everything broke down. Lady Sybil -- the most open-minded daughter, who married former family chauffeur Tom Branson -- died during childbirth, setting off a series of events on both sides of the economic divide that threatened to tear apart the house.

Sunday’s finale won’t be ruined in this article, but suffice it to say the drama is hardly finished.

The reaction to the show, first in the U.K. and then in the U.S., has been overwhelming. The Internet has been inundated each Monday over the past six weeks with “Downton Abbey”-related analysis. Fans of the show run the gambit from country star Reba McEntire to comedian Patton Oswalt, who live-tweets new episodes every Sunday night.

Series creator Julian Fellowes, who previously wrote the film “Gosford Park,” explained the program’s widespread appeal during an interview with the Wall Street Journal. He credited the show with treating every character with a degree of seriousness that isn’t seen in other television series.

“I don’t think we patronize the servants; we don’t make them comedic,” Fellowes said. “Nor do we automatically hate the family or regard them as selfish and mendacious and so on. I like the characters to disagree, and the audience can see both points of view, so that neither is being ludicrous or unreasonable. It just always seems to me more interesting if you're slightly torn as to which side you're on."

The third-season finale of “Downton Abbey” in the U.S. will air Sunday at 9 p.m. EST. It is available for online streaming.