First, I promise I won’t have ANY “The Dark Knight Rises” spoilers in this column. I’m nice like that. Also, it’s no spoiler to say the film, which opens Friday, clocks in at a hefty two hours and 40 minutes (and that’s without previews).

A movie that long often gets described as “epic,” because people forget “epic” and “long” are not, in fact, synonyms. This film is an epic, though, and not just because you have to make sure you pee before finding your seat.

“The Dark Knight Rises” tells the story of a hero whose deeds shape the very culture of a society. Within the story space, that culture is Gotham City’s, but what director Christopher Nolan has done with this final piece of his trilogy is expand the scope of Batman’s reach into our own society. The entire film is a (sometimes heavy-handed) political allegory on the questions of property, identity, loyalty and responsibility.

A long movie isn’t necessarily an epic — look at “Gone With the Wind,” which is a million years long but manages to sidestep any serious consideration of questions like, “Should people own other people?” “Rises” is an epic in the classical sense: It asks big questions in big ways, and that has to take some time.