I hate chick lit and get bored with torture porn, but it turns out that putting the two of them together creates the proverbial peanut butter chocolate awesomeness. If you eat Jennifer's Body like weird candy, it works. Spoilers ahead!
Jennifer's Body is as simple as chocolate-spiked spit and as complicated as you want it to be. I like that in a movie.
Here's the simple part: Nice, nerdy Needy (the awesome Amanda Seyfried from Big Love) is BFFs with the bitchy hottie Jennifer (Megan Fox). They live in a small, Minnesota town where such an unlikely pairing is possible. There are so few kids in their town that two little girls who played in the sandbox together can stay friends as teens. But there's a problem. Jennifer is always pushing Needy around.
That's how the two wind up at a show for some lame indie rock band called Low Shoulder. A band whose lead singer Jennifer is scheming to hook up with. It turns out that Low Shoulder has a scheme, too: They want to sacrifice a virgin to Satan so that their band will achieve some success without having to do something "lame" like go on Letterman. Because they're in such a backwoods town, they assume Jennifer is a virgin. But as she says later, "I'm not even a backdoor virgin." Turns out when you sacrifice a non-virgin to Satan, it causes the sacrifice to go all undead demon on your ass.
And that's when things get sick. Jennifer has to drink blood to survive, and she's not satisfied just eating dumbass members of the football team. So she starts going after people Needy likes, including Needy's floppy-haired, cute boyfriend Chip. There's an amazing awkward/cute/horrifying scene where Chip and Needy are losing their virginity together, intercut with Jennifer sipping blood out of the ripped-open torso of another guy Needy has an unacknowledged crush on.
Once Needy figures out Jennifer is a demon, she sets out to stop her. Of course everything culminates in a Needy vs. Jennifer vs. Chip showdown at the prom, an event that is hellish for girls even if they don't have best frenemies who are monsters.
Sure it's a cliched structure; you've seen it a thousand times before. That's the way horror movies work, though. They offer up a generic story and the good parts, the original parts, come in the little tweaks and fucked-up details that offer you a glimpse of the real-life horrors that lurk beneath the CG fantasy. And that's why Jennifer's Body is so rewarding as a movie: Things get really complicated the more you think about how this movie overturns your expectations.
So now for the complicated part. Let's begin with how this flick breaks one of the cardinal rules of small-scale horror. Here you have a female monster menacing a female character. Usually female monsters - especially sexy ones like Jennifer - are out to get men. Female vampires chomp on men; Grendel's mom tries to smack down Beowulf; the Species chick murders guys who are boning her. There are exceptions, like the woman vs. woman fights in Aliens or Friday the 13th (the very first movie). But those movies are quite memorable because they fly in the face of our expectations.
Jennifer eats men, but she does it to get at Needy. She eats the men Needy loves. As director Karyn Kusama has said, Jennifer's Body is a movie about toxic friendships between women. By placing this story in the context of a monster movie, it also does something interesting. First, it acknowledges that women are horribly dangerous, which you already knew if you watched The Sarah Connor Chronicles. More importantly, it acknowledges that women are dangerous to other women. Not just in a mean girls way, but in an "I will rip your lungs out" way.