Just when I thought I had a grasp of what kind of movies are sure to get a sequel or two, and which ones won’t, all my assumptions are being turned upside down. Spider Man? Sure. Pirates? Of course. But a sequel to An Inconvenient Truth? And one for Hal Hartly’s Henry Fool (which, incidentally is one of my favorite films)? Go figure.

Yes, it appears to be true. We’re going to be treated to a sequel of an informative (if slightly slow) documentary about global warming, and another for a high quality film with very little action and rather unpleasant characters. For An Inconvenient Truth Part 2 (I know, it gets your heart beating faster, doesn’t it?), director Davis Guggenheim is scheduled to meet with Paramount next week, so it’s too soon for details. (Will the original film’s star, Al Gore, agree to a sequel? The suspense…)

For the Henry Fool sequel, Hartly made Fay Grim, which picks up seven years later and focuses on the Parker Posey character by the same name. Somehow, Hartly manages to take a movie based entirely in a Queens neighborhood, and move its sequel to Paris, where the CIA also plays a role. Not your typical sequel (but I can’t wait to see it–check out the trailer at Spout).

So do these new developments tell us anything about the future of the sequel? Probably not. Some of the best documentary sequels (although most people don’t call them that) have been around for a while–director Michael Apted’s Up Series (28 Up, 35 Up, etc.), which he began filming in 1963. (Apted began chronicling the lives of 14 seven year olds that year, following up with “sequels” every seven years after.) It’s a brilliant series, but it hasn’t shifted the way most studios think about doing sequels. Neither did Smoke or its sequel (of sorts) Blue in the Face, another example of an atypical movie sequel set. No, it seems the decision to make your average sequel is generally all about what made a lot of money the first time around and might have enough buzz surrounding it to sustain another go. Wouldn’t it be great if the decision to create a sequel was based on the story, and whether it was worthy of another go?