Downton Abbey stands in defiance of those who declared that the age of the British costume drama is dead, says actor Hugh Bonneville, among the stars of the hit British TV drama.

The veteran actor, who plays Robert Crawley, Earl of Grantham, says that the must-see television drama intrigued him from the moment he first read the pilot episode's script, which was full of vivid, fascinating characters.

The appeal of the show is also tied to the mix of elements inspired by some of creator Julian Fellowes' own favourite TV programs, such as long-running ensemble drama Coronation Street and fast-paced U.S. political saga The West Wing, Bonneville told CBC's Q.

With Downton Abbey, "there's the element of soap, there's the multi-stranded storylines, a great pace to it and characters that even if you get bored of one, there's another one along in about 32 seconds," he said.

In the attached audio, Bonneville talks to Q guest host Kevin Sylvester about Downton's meticulous details, class tensions and upcoming plot shockers.

"There's one particular big shock coming up which really pulls the rug out from the idea that this is just a cute, cozy show about people losing cufflinks occasionally," he says.

The fourth season of Downton Abbey debuts in North America on Sunday, on PBS and Vision.