I had fun during my residency this week telling the students about basic three act structure. Or, better put: You stick a guy up a tree. Throw rocks at him. Then he gets down again.
I explain it using Harry Potter. The tree is the PROBLEM of the series: namely, Voldemort wants to kill Harry. The rocks are all the bad stuff that happens to Harry. And the rocks start out quite little, like sand or gravel. The Dursleys are mean. Draco Malfoy is a tool. Snape is nasty. There's a troll in the bathroom. But as the series progresses, those rocks start getting bigger and bigger. Now Draco Malfoy is EVIL and trying to kill Dumbledore! Instead of Snape we've got Umbridge who is trying to destroy Hogwarts! And instead of the troll we've got DEMENTORS and CREEPY NO NOSE VOLDEMORT.
And just when we think Harry can't take it anymore and one of those boulders is going to smash his brains, that's when he gets himself out of the tree.
And he's got to get himself out.
Because if, during the final battle of Harry Potter, some dude called Bob ran in and killed Voldemort, I'd be left wondering how come I didn't just read 7 books about Bob. Harry must bring about his own conclusion, using all the tools and tricks he's learnt defending himself from all those rocks we threw at him.
And that's why I don't like Twilight. Because Bella doesn't get herself out of the tree. She just waits until Edward comes and spider-monkeys her out, or Sixpack Mcgee brings the rescue-wolves.