Helen Mirren is nominated for an Oscar for Best Actress for the title role in The Queen, and I walked out of the theater feeling sure she’ll sweep the category. I also walked out being surprised how satisfying this movie is.

I wasn’t looking forward to a film about the inner workings of the British monarchy – it sounded like a stuffy drawing-room melodrama. But it’s not. Going inside the royal family in the days following the death of Princess Diana in 1997, the story pits the frosty traditionalism of Queen Elizabeth against the charismatic media savvy of a young Tony Blair. Running an unpadded 97 minutes, the film never drags.

It’s interesting, and even funny, to watch Blair attempt to nudge Elizabeth toward acknowledging and publicly mourning the death of Diana, whose heavy-breathing People magazine stardom (among other things) made her very much persona non grata among the airless royal family.

It’s poignant, too, when Elizabeth realizes the world is shifting under her feet. The Queen explores what happens when we’re faced with the need to change those things we hold most sacred. Mirren’s ability to take us along on that journey makes the movie a winner.

I noticed the average age in the movie theater was about 60, so I’m guessing the film will reach a wider audience after Mirren accepts her Oscar in late February.