The B story gives us a breather.

Let's take Legally Blonde, for instance. The B story is Elle's relationship with the manicurist she meets in Boston. And it is a much needed break from the A story. We've met Elle. She's been dumped. She's decided to go to Law School. She gets there. And school is tough. Well, enough already, let's have a little time-out! Let's go slightly off theme here and meet someone new. Thus, the manicurist. And yes, while it is not a traditional boy-girl love story, it is in fact "the love story." It's where Elle will be nurtured. It is also the place where Elle confides what she is learning in the School of Hard Knocks she's experiencing at Harvard Law — and the place from which she'll draw the strength she needs for the final push into Act Three and ultimate victory.

The B story is also very often a brand new bunch of characters. We have not always met the B story players in the first IO pages of the screenplay. We did not even know they existed. But since Act Two is the antithesis, they are the upside down versions of those characters who inhabit the world of Act One. Again, the B story ally in Legally Blonde is a perfect example. Isn't Jennifer Goolidge, the wonderful actress who portrays manicurist Paulette Bonafonte, the funhouse mirror version of the girls from Elle's sorority house back at UCLA? This is why the character is so successful. She is a classic anti-thesis creature.

The B story then does a lot. And you must have one. It provides not only the love story and a place to openly discuss the theme of your movie, but gives the writer the vital "cutaways" from the A story. And it starts on 3O.