Funny *****spoiler, major spoiler ahead*****
really funny Zep.
And what in the world did we do before Wiki?
Thanks Bison.
Here is my advice to the OP, Sadie.
Find the script for one of the ensemble films that Plot listed and read the script. THEN take a yellow highlighter and mark ALL the moments in that script that match Bison's definition.
Uh, let's take Crash because I've seen that one.
Think about it carefully.
Study the moments. You won't be marking EVERY little sip of coffee or stroll through the park BUT MOMENTS THAT SHIFT THE STORY.
(for example, in Crash when the two black teenagers steal the white couple's car, or when the DA's wife falls down the stairs.)
Next get a green highlighter or a red pen and mark the two or three MAJOR points. These are the moments where the story LEAPS forward. Like, uh, OH I can't rememember the very first one (what some would call the Inciting Incident) but a big one would be when the Hindu store owner goes to shoot the locksmith, hits the Mexican daughter instead.
And another would be when the young black teenager is killed.
NOW, with those clearly marked, read the script again and consider how the writer put all the scenes and events together to move from one point to the other.
Hope that helps.
If not, let me know and I'll pull some more half baked advice out of my backside.
